Buick Encore: Diagnostic information and procedures
SCHEMATIC WIRING DIAGRAMS
HVAC WIRING SCHEMATICS (ENCORE)
Power, Ground, and Blower Motor
Fig. 1: Power, Ground, and Blower Motor
Compressor Controls
Fig. 2: Compressor Controls
Duct and Evaporator Temperature Sensors
Fig. 3: Duct and Evaporator Temperature Sensors
Mode and Temperature Control Actuators
Fig. 4: Mode and Temperature Control Actuators
Sunload Sensor and Windshield Temperature Sensor
Fig. 5: Sunload Sensor and Windshield Temperature Sensor
DIAGNOSTIC INFORMATION AND PROCEDURES
HVAC COMPONENT REPLACEMENT REFERENCE
HVAC Component Replacement Reference
DIAGNOSTIC CODE INDEX
DIAGNOSTIC CODE INDEX
DTC B0163, B0183, OR B1405: Passenger compartment
temperature sensor/solar load sensor/control module voltage reference
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptors
DTC B0163
Passenger Compartment Temperature Sensor Circuit
DTC B0183
Solar Load Sensor Circuit
DTC B1405
Control Module Voltage Reference Output 2 Circuit
For symptom byte information, refer to Symptom Byte List .
Diagnostic Fault Information
Circuit/System Description
The ambient light/sunload sensor integrates the sunload and passenger
compartment temperature functions
within a single assembly.
The solar sensor uses 4 unique circuits as detailed below:
- Low reference circuit - This is a common ground for the ambient light/sunload
sensor assembly.
- Temperature signal circuit - This is the signal circuit for the
temperature sensor.
- Clock signal circuit - This has 2 functions, via a high side PWM signal,
the HVAC control module
supplies power to the sensor as well as a clock input for the sensor
microprocessor.
- Sunload signal circuit - This is used as an output from the solar sensor
to the HVAC control module to
transmit sun heat (IR) intensity, elevation, and azimuth data.
The passenger compartment temperature sensor is a negative temperature
coefficient thermistor. As the air
temperature increases, the sensor resistance decreases. The sensor signal varies
between 0-5 V.
Bright or high intensity light causes the vehicles interior temperature to
increase. The automatic HVAC system
compensates for the increased temperature by diverting additional cool air into
the vehicle.
Conditions for Running the DTC
- Ignition ON
- The HVAC control module is ON.
Conditions for Setting the DTC
B0163 02
The input signal is out of range. The HVAC control module detects voltage
less than 0.1 V on the temperature
signal circuit.
B0163 05
The input signal is out of range. The HVAC control module detects voltage
less than 0.1 V on the temperature
signal circuit.
B0163 05
The input signal is out of range. The HVAC control module detects voltage
greater than 4.9 V on the
temperature signal circuit.
B0183 02
The input signal is out of range. The HVAC control module detects voltage
less than 0.1 V on the solar sensor
signal circuit.
B0183 05
The input signal is out of range. The HVAC control module detects voltage
greater than 4.9 V on the solar
sensor signal circuit.
B1405 02
The input signal is out of range. The HVAC control module detects voltage
less than 10 V on the clock/power
supply circuit.
B1405 05
The input signal is out of range. The HVAC control module detects a short to
voltage or an open the
clock/power supply circuit.
Action Taken When the DTC Sets
B0163 02, B0163 05, B0183 02, B0183 05
The system will use the last valid values as a default.
B1405 02, B1405 05
If no value is read at the time of fault, the HVAC control module uses 0 W/m2
as intensity.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Reference Information
Schematic Reference
HVAC Schematics (Encore)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - Encore
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Verify DTCs B0163 and B0183 are not both set concurrently.
If both DTCs are set
Refer to Low Reference Test.
- If both DTCs are not set
- Verify DTC B0163, B0183, or B1405 is not set.
If one of the DTCs is set
Refer to the appropriate diagnostic in Circuit/System Testing.
If none of the DTCs are set
- Verify the B10B Ambient Light/Sunload Sensor is accurate.
If the sensor is not accurate
- Perform the following Circuit/System Testing in the order listed below:
- Circuit/System Testing - Low Reference Test
- Circuit/System Testing - DTC B0163
- Circuit/System Testing - DTC B1405
- Circuit/System Testing - DTC B0183
If the sensor is accurate
- All OK.
Circuit/System Testing
Low Reference Test
NOTE: You must perform the Circuit/System Verification before
proceeding with
Circuit/System Testing.
- Ignition OFF and all vehicle systems OFF, disconnect the harness
connector at the B10B Ambient
Light/Sunload Sensor. It may take up to 10 min for all vehicle systems to
power down.
NOTE: The scan tool must be disconnected from the vehicle before
performing
the next test.
- Test for less than 10 ohms between the low reference circuit terminal 6
and ground.
- Ignition OFF, disconnect the harness connector at the K33 HVAC Control
Module.
- Test for less than 2 ohms in the low reference circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If less than 10 ohms
- Test or replace the B10B Ambient Light/Sunload Sensor.
DTC B0163
NOTE: You must perform the Circuit/System Verification before
proceeding with
Circuit/System Testing.
- Ignition OFF, disconnect the harness connector at the B10B Ambient Light/Sunload
Sensor, ignition ON.
- Verify the scan tool Passenger Compartment Air Temperature (Unfiltered)
parameter is less than -37ºC (-
35ºF).
If -37ºC (-35ºF) or greater
- Ignition OFF, disconnect the harness connector at the K33 HVAC Control
Module.
- Test for infinite resistance between the signal circuit terminal 3 and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K33 HVAC Control Module.
If less than -37ºC (-35ºF)
- Install a 3 A fused jumper wire between the signal circuit terminal 3
and the low reference circuit
terminal 6.
- Verify the scan tool parameter Passenger Compartment Air Temperature (Unfiltered)
parameter is greater
than 78ºC (172ºF).
If 78ºC (172ºF) or less
- Ignition OFF, remove the jumper wire and disconnect the harness
connector at the K33 HVAC
Control Module, ignition ON.
- Test for less than 1 V between the signal circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Ignition OFF.
- Test for less than 2 ohms in the signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If greater than 78ºC (172ºF)
- Test or replace the B10B Ambient Light/Sunload Sensor.
DTC B0183
NOTE: You must perform the Circuit/System Verification before
proceeding with
Circuit/System Testing.
- Ignition OFF, disconnect the harness connector at the B10B Ambient Light/Sunload
Sensor, ignition ON.
- Test for 4.8-5.2 V between the signal circuit terminal 4 and ground.
If less than 4.8 V
- Ignition OFF, disconnect the harness connector at the K33 HVAC Control
Module.
- Test for infinite resistance between the signal circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance
- Test for less than 2 ohms in the signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If greater than for 5.2 V
- Ignition OFF, disconnect the harness connector at the K33 HVAC Control
Module, ignition ON.
- Test for less than 1 V between the signal circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K33 HVAC Control Module.
If between 4.8-5.2 V
- Test or replace the B10B Ambient Light/Sunload Sensor.
- Verify DTC B0183 did not reset.
If DTC B0183 reset
Replace the K33 HVAC Control Module.
If DTC B0183 did not reset
- All OK.
DTC B1405
NOTE: You must perform the Circuit/System Verification before
proceeding with
Circuit/System Testing.
- Ignition OFF, disconnect the harness connector at the B10B Ambient Light/Sunload
Sensor, ignition ON.
- Test for greater than 10 V between signal circuit terminal 2 and ground.
If less than 10 V
- Ignition OFF, disconnect the harness connector at the K33 HVAC Control
Module.
- Test for infinite resistance between signal circuit terminal 2 and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance
- Test for less than 2 ohms in the signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If 10 V or greater
- Ignition OFF, disconnect the harness connector at the K33 HVAC Control
Module, ignition ON.
- Test for less than 1 V between the signal circuit terminal 2 and ground.
If 1 V or greater
Repair the short to voltage on the circuit.
If less than 1 V
- Test or replace the B10B Ambient Light/Sunload Sensor.
- Verify DTC B1405 did not reset.
If DTC B1405 reset
Replace the K33 HVAC Control Module.
If DTC B1405 did not reset
- All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- HVAC Component Replacement Reference
- Control Module References for HVAC control module replacement,
programming and setup
DTC B0173, B0178, B0509, B0514 OR B3933: DUCT AIR TEMPERATURE SENSOR/EVAPORATOR
TEMPERATURE SENSOR
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptors
DTC B0173 02
Upper Left Duct Air Temperature Sensor Circuit Short to Ground
DTC B0173 05
Upper Left Duct Air Temperature Sensor Circuit High Voltage/Open
DTC B0178 02
Lower Left Duct Air Temperature Sensor Circuit Short to Ground
DTC B0178 05
Lower Left Duct Air Temperature Sensor Circuit High Voltage/Open
DTC B0509 02
Upper Right Duct Air Temperature Sensor Circuit Short to Ground
DTC B0509 05
Upper Right Duct Air Temperature Sensor Circuit High Voltage/Open
DTC B0514 02
Lower Right Duct Air Temperature Sensor Circuit Short to Ground
DTC B0514 05
Lower Right Duct Air Temperature Sensor Circuit High Voltage/Open
DTC B3933 02
Air Conditioning Evaporator Temperature Sensor Circuit Short to Ground
DTC B3933 05
Air Conditioning Evaporator Temperature Sensor Circuit High Voltage/Open
Diagnostic Fault Information
Circuit/System Description
The air temperature sensors are a 2-wire negative temperature coefficient
thermistor. The vehicle uses the
following air temperature sensors:
- Air temperature sensor - left upper
- Air temperature sensor - left lower
- Air temperature sensor - right upper
- Air temperature sensor - right lower
- A/C evaporator temperature sensor
This sensor operates using signal and low reference circuits. As the air
temperature surrounding the sensor
increases, the sensor resistance decreases. The sensor sends a signal voltage
between 0-5 V. If the HVAC
control module detects a malfunctioning sensor the software uses a default air
temperature value. The default
action ensures that the HVAC system can adjust the inside air temperature near
the desired temperature until the
condition is corrected.
Conditions for Running the DTC
- Ignition ON.
- The HVAC control module is ON.
Conditions for Setting the DTC
The HVAC control module detects the sensor signal out of range. The signal
voltage is less than 0.1 V or
greater than 4.9 V for more than 50 ms.
Action Taken When the DTC Sets
The system operates using a default value.
Conditions for Clearing the DTC
The sensor signal is within specified range between 0.1-4.9 V.
Reference Information
Schematic Reference
HVAC Schematics (Encore)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - Encore
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON.
- Verify DTC B3933 is not set.
If DTC B3933 is set
Refer to Circuit/System Testing - Without Scan Tool Support.
If DTC B3933 is not set
- Verify the appropriate temperature sensor has a parameter displayed in
HVAC scan tool information.
If there is no scan tool parameter
Refer to Circuit/System Testing - Without Scan Tool Support.
If there is a scan tool parameter
- Refer to Circuit/System Testing - With Scan Tool Support
Circuit/System Testing
With Scan Tool Support
- Ignition OFF and all vehicle systems OFF, disconnect the harness
connector at the appropriate
temperature sensor. It may take up to 10 min for all vehicle systems to
power down.
NOTE: The scan tool must be disconnected from the vehicle
before performing
the next test.
- Test for less than 10 ohms between the low reference circuit terminal B
and ground.
If 10 ohms or greater
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module.
- Test for less than 2 ohms in the low reference circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If less than 10 ohms
- Ignition ON.
- Verify the appropriate scan tool temperature sensor parameter is less
than -37ºC (-35ºF)
If greater than -37ºC (-35ºF)
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module.
- Test for infinite resistance between the signal circuit terminal A and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K33 HVAC Control Module.
If -37ºC (-35ºF) or less
- Install a 3 A fused jumper wire between the signal circuit terminal A
and the low reference circuit
terminal B.
- Verify the scan tool temperature sensor parameter is greater than 77ºC
(170ºF).
If less than 77ºC (170ºF)
- Ignition OFF, remove the jumper wire and disconnect the harness
connectors at the K33 HVAC
Control Module, ignition ON.
- Test for less than 1 V between the signal circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Ignition OFF
- Test for less than 2 ohms in the signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If 77ºC (170ºF) or greater
- Test or replace the temperature sensor.
Without Scan Tool Support
- Ignition OFF and all vehicle systems OFF, disconnect the harness
connector at the appropriate
temperature sensor. It may take up to 10 min for all vehicle systems to
power down.
NOTE: The scan tool must be disconnected from the vehicle before
performing
the next test
- Test for less than 10 ohms between the low reference circuit terminal B
and ground.
If 10 ohms or greater
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module.
- Test for less than 2 ohms in the low reference circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If less than 10 ohms
- Test for 4.8-5.2 V between the signal circuit terminal A and ground.
If less than 4.8 V
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module.
- Test for infinite resistance between the signal circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance
- Test for less than 2 ohms in the signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If greater than 5.2 V
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module, ignition ON.
- Test for less than 1 V between the signal circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K33 HVAC Control Module.
If between 4.8-5.2 V
- Test or replace the temperature sensor.
- Operate the vehicle within the Conditions for Running the DTC. You may
also operate the vehicle within
the conditions that you observed from the Freeze Frame/Failure Records data.
- Verify the DTC does not set.
If the DTC sets
Replace the K33 HVAC Control Module.
If the DTC does not set
- All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair
- HVAC Component Replacement Reference
- Control Module References for HVAC control module replacement,
programming and setup
DTC B018A, B048C, B048F, OR B1395: Windshield temperature sensor/humidity
sensor/control module voltage reference
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptors
DTC B018A
Windshield Temperature Sensor Circuit
DTC B048C
Humidity Sensor Humidity Circuit
DTC B048F
Humidity Sensor Temperature Circuit
DTC B1395
Control Module Voltage Reference Output Circuit
For symptom byte information, refer to Symptom Byte List .
Diagnostic Fault Information
Circuit/System Description
The windshield temperature and inside moisture sensor includes the relative
humidity sensor, windshield
temperature sensor and humidity sensing element temperature sensor all in one
assembly.
This sensor assembly provides information about:
- Relative humidity level at the windshield inside the vehicle
- Temperature of the windshield inside the vehicle
- Temperature of the humidity sensor element
The relative humidity sensor measures the relative humidity of the
compartment side of the windshield. It also
detects the temperature of the windshield surface on the compartment side. Both
values are used as control
inputs for the HVAC control module application to calculate the fog risk on
windshield compartment side and
ability to reduce fuel consumption by decreasing A/C compressor usage to a
minimum without causing any fog.
The sensor will also enable partial recirculation mode in order to improve heat-up
performance of the passenger
compartment under cold ambient temperature conditions without the risk of mist
build-up on the windshield.
The humidity sensor element temperature sensor supplies the temperature of the
humidity sensor element. It is
only needed if the thermal contact between the humidity sensing element and the
inside windshield surface is
not sufficient.
Conditions for Running the DTC
- Ignition ON.
- The HVAC control module is ON.
Conditions for Setting the DTC
B018A 02, B048C 02, or B048F 02
The HVAC control module detects the sensor signal out of range. The signal
voltage is less than 0.1 V for more
than 50 ms.
B018A 05, B048C 05, B048F 05 or B1395 07
The HVAC control module detects the sensor signal out of range. The signal
voltage is greater than 4.9 V for
more than 50 ms.
B1395 03
The HVAC control module detects the 5 V reference voltage out of range. The 5
V reference voltage is less
than 4.5 V for more than 50 ms.
B1395 07
The HVAC control module detects the 5 V reference voltage out of range. The 5
V reference voltage is greater
than 5.5 V for more than 50 ms.
Action Taken When the DTC Sets
- The system will use the last valid values as default.
- If no value is read at the time of fault, the HVAC control module uses
60% for humidity.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Reference Information
Schematic Reference
HVAC Schematics (Encore)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - Encore
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF and all vehicle systems OFF, disconnect the harness
connector at the B160 Windshield
Temperature and Inside Moisture Sensor. It may take up to 10 min for all
vehicle systems to power down
NOTE: The scan tool must be disconnected from the vehicle before
performing
the next test.
- Test for less than 10 ohms between the low reference circuit terminal 3
and ground.
If 10 ohms or greater
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module.
- Test for less than 2 ohms in the low reference circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If less than 10 ohms
- Ignition ON.
- Test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and
ground.
If less than 4.8 V
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module.
- Test for infinite resistance between the 5 V reference circuit and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance
- Test for less than 2 ohms in the 5 V reference circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If greater than 5.2 V
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module, ignition ON.
- Test for less than 1 V between the 5 V reference circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K33 HVAC Control Module.
If between 4.8-5.2 V
- Verify the scan tool parameters listed below are less than -37ºC
(-35ºF).
- Windshield Temperature
- Passenger Compartment Humidity Sensor Temperature
If -37ºC (-35ºF) or greater
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module.
- Test for infinite resistance between the signal circuit terminals listed
below and ground:
- Windshield temperature sensor signal terminal 4
- Passenger compartment humidity sensor temperature signal terminal 5
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K33 HVAC Control Module.
If less than -37ºC (-35ºF)
- Install a 3 A fused jumper wire between the low reference circuit
terminal 3 and each signal circuit terminal listed below:
- Windshield temperature sensor signal terminal 4
- Passenger compartment humidity sensor temperature signal terminal 5
- Verify the appropriate scan tool parameter listed below is greater than
114ºC (238ºF).
- Windshield Temperature
- Passenger Compartment Humidity Sensor Temperature
If 114ºC (238ºF) or less
- Ignition OFF, remove the jumper wire and disconnect the harness
connectors at the K33 HVAC
Control Module, ignition ON.
- Test for less than 1 V between the signal circuit terminals listed below
and ground:
- Windshield temperature sensor signal terminal 4
- Passenger compartment humidity sensor temperature signal terminal 5
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Test for less than 2 ohms in the signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If greater than 114ºC (238ºF)
- Remove the jumper wire.
- Verify the scan tool Passenger Compartment Humidity parameter is greater
than 95%.
If 95% or less
- Ignition OFF, disconnect the harness connectors at the K33 HVAC Control
Module, ignition ON.
- Test for infinite resistance between the signal circuit terminal 2
and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K33 HVAC Control Module.
If greater than 95%
- Install a 3 A fused jumper wire between the passenger compartment
humidity signal circuit terminal 2
and the low reference circuit terminal 3.
- Verify the scan tool Passenger Compartment Humidity Sensor parameter is
less than 5%.
If 5% or greater
- Ignition OFF, remove the jumper wire and disconnect the harness
connectors at the K33 HVAC
Control Module, ignition ON.
- Test for less than 1 V between the signal circuit terminal 2 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Test for less than 2 ohms in the signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If less than 5%
- Test or replace the B160 Windshield Temperature and Inside Moisture
Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- HVAC Component Replacement Reference
- Control Module References for HVAC control module replacement,
programming and setup
DTC B0193: Front blower motor speed circuit
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptors
DTC B0193 01
Front Blower Motor Speed Circuit Short to Battery
DTC B0193 06
Front Blower Motor Speed Circuit Low Voltage/Open
Diagnostic Fault Information
Circuit/System Description
The blower motor control module is an interface between the HVAC control
module and the blower motor. The
blower motor control module has 4 circuits: a B+ input, a signal input from the
HVAC control module, a B+
output to the blower motor, and a low side pulse width modulation (PWM) output.
The HVAC control module
provides a low side (PWM) signal to the blower motor control module in order to
request the blower motor
speed. The blower motor control module grounds the blower motor using a low side
PWM signal in order to
vary the blower motor speed.
Conditions for Running the DTC
- Ignition ON.
- The HVAC control module is ON.
Conditions for Setting the DTC
B0193 01
The voltage at the HVAC control module output to the blower motor control
module is always high.
B0193 06
The voltage at the HVAC control module output to the blower motor control
module is always low or
fluctuating.
Action Taken When the DTC Sets
The blower motor is inoperative
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Diagnostic Aids
Inspect the motor shaft for rust or other foreign material which may prohibit
proper motor operation.
If the motor operates properly please reinstall it and check for Preliminary
Information or Technical Service
Bulletins.
Reference Information
Schematic Reference
HVAC Schematics (Encore)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - Encore
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF and all vehicle systems OFF, disconnect the X1 harness
connector at the K8 Blower Motor
Control Module. It may take up to 2 min for all vehicle systems to power
down.
- Test for less than 10 ohms between the ground circuit terminal 5
and ground.
If 10 ohms or greater
- Ignition OFF.
- Test for less than 2 ohms in the ground circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, repair the open/high resistance in the ground
connection.
If less than 10 ohms
- Ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 6 and
ground.
If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF, remove the test lamp.
- Test for less than 2 ohms in the B+ circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, verify the fuse is not open and there is voltage at
the fuse.
If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF, remove the test lamp.
- Test for infinite resistance between the B+ circuit terminal 6 and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance
- Disconnect the X2 harness connector at the K8 Blower Motor Control
Module and disconnect the
harness connector at the M8 Blower Motor.
- Test for infinite resistance between the M8 Blower Motor control circuit
terminal B and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, test or replace the M8 Blower Motor.
If the test lamp illuminates
- Remove the test lamp.
- Test for 2.6-3.2 V between the control circuit terminal 3 and
ground.
If less than 2.6 V
- Ignition OFF, disconnect the X2 harness connector at the K33 HVAC
Control Module, ignition
ON.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance.
- Test for less than 2 ohms in the control circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms replace the K33 HVAC Control Module.
If greater than 3.2 V
- Ignition OFF, disconnect the X2 harness connector at the K33 HVAC
Control Module, ignition
ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K33 HVAC Control Module.
If between 2.6-3.2 V
- Ignition OFF, connect the X1 harness connector at the K8 Blower Motor
Control Module and disconnect
the harness connector at the M8 Blower Motor, ignition ON and blower ON.
- Verify a test lamp illuminates between the control circuit terminal 1
and ground.
If the test lamp does not illuminate
- Ignition OFF, disconnect the X2 harness connector at the K8 Blower Motor
Control Module.
- Test for less than 2 ohms in the control circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms replace the K8 Blower Motor Control Module.
If the test lamp illuminates
- Connect a test lamp between control circuit terminal 1 and control
circuit terminal 2.
- Verify the test lamp becomes progressively brighter as the blower speed
is increased and progressively
dimmer as the blower speed is decreased.
If the test lamp does not illuminate
- Ignition OFF, disconnect the X2 harness connector at the K8 Blower Motor
Control Module,
ignition ON.
- Test for less than 1 V between the control circuit terminal 1 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Test for less than 2 ohms in the control circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms replace the K8 Blower Motor Control Module.
If the test lamp illuminates, but does not change in brightness
- Ignition OFF, disconnect the X2 harness connector at the K8 Blower Motor
Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K8 Blower Motor Control Module.
If the test lamp changes in brightness as the blower speed is changed
- Test or replace the M8 Blower Motor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- HVAC Component Replacement Reference
- Control Module References for HVAC control module replacement,
programming and setup
DTC B0223, B022A, B0233, B023A, B0408, OR B0418:
Recirculate position command/air flow control/temperature control circuit
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptor
DTC B0223 01
Recirculate Position Command 1 Circuit Short to Battery
DTC B0223 06
Recirculate Position Command 1 Circuit Low Voltage/Open
DTC B022A 01
Recirculate Position Command 2 Circuit Short to Battery
DTC B022A 06
Recirculate Position Command 2 Circuit Low Voltage/Open
DTC B0233 01
Air Flow Control Circuit Short to Battery
DTC B0233 06
Air Flow Control Circuit Low Voltage/Open
DTC B023A 02
HVAC Actuators Supply Voltage Short to Ground
DTC B0408 01
Main Temperature Control Circuit Short to Battery
DTC B0408 06
Main Temperature Control Circuit Low Voltage/Open
DTC B0418 01
Right Temperature Control Circuit Short to Battery
DTC B0418 06
Right Temperature Control Circuit Low Voltage/Open
Diagnostic Fault Information
Circuit/System Description
Stepper motors are used for temperature regulation, air distribution control
and recirculation door control.
With the switches and dials on the HVAC controls, air temperature door position,
mode door position and
recirculation door position can be selected. The selected values are passed to
the HVAC control module via
serial data. The HVAC control module supplies a 12 V control voltage to the
stepper motors and energizes the 4
stepper motor coils with a pulsed ground signal. The stepper motors move the
appropriate doors into the
calculated positions, in order to reach the desired positions.
Conditions for Running the DTC
- Ignition ON.
- The HVAC control module is ON.
Conditions for Setting the DTC
B023A 02
The stepper motors supply output is shorted to ground.
B0223 01, B022A 01, B0233 01, B023A 01, B0408 01 or B0418 01
At least one control circuits of the appropriate stepper motor is shorted to
voltage when motor starts moving.
Faults are not detected when motor is already running or target position is
already reached.
B0223 06, B022A 06, B0233 06, B0233 06, B0408 06 or B0418 06
At least one control circuits of the appropriate stepper motor is shorted to
ground or open when motor starts moving. Faults are not
detected when motor is already running or target position is already reached.
Action Taken When the DTC Sets
B023A
- The affected output will be switched off for hardware protection.
- All stepper motors are deactivated.
B0223, B022A, B0233, B0408 or B0418,
- The affected output will be switched off for hardware protection.
- The affected stepper motor is deactivated.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Reference Information
Schematic Reference
HVAC Schematics (Encore)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - Encore
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Perform the Actuator Recalibration procedure.
- Verify the concern or DTC has been corrected.
If the concern or DTC has not been corrected
- Verify DTC B023A is not set.
Refer to Circuit/System Testing - DTC B023A.
Refer to Circuit/System Testing - DTC B0223, B022A, B0233, B0408 or B0418.
If the concern or DTC has been corrected
- All OK.
Circuit/System Testing
DTC B023A
- Ignition OFF and all vehicle systems OFF, disconnect the harness
connector at the components listed
below. It may take up to 2 min for all vehicle systems to power down.
- M37 Mode Door Actuator
- M46 Air Recirculation Door Actuator
- M6L Air Temperature Door Actuator - Left
- M6R Air Temperature Door Actuator - Right
- Disconnect the X3 and X4 harness connectors at the K33 HVAC Control
Module.
- Test for infinite resistance between the K33 HVAC Control Module 12 V
reference circuit terminal 15
X3 and ground.
If less than infinite resistance
Repair the short to ground on the circuit.
If infinite resistance
- Ignition ON.
- Test for less than 1 V between the K33 HVAC Control Module 12 V
reference circuit terminal 15 X3 and
ground.
If 1 V or greater
Repair the short to voltage on the circuit.
If less than 1 V
- Connect the X3 and X4 harness connectors at the K33 HVAC Control Module,
ignition ON.
- Clear all DTCs.
- Verify DTC B023A is not set.
If the DTC is set.
Replace the K33 HVAC Control Module.
If the DTC is not set.
- Verify DTC B023A does not set after connecting each of the components
listed below one at a time and
operating them through their full range.
- M37 Mode Door Actuator
- M46 Air Recirculation Door Actuator
- M6L Air Temperature Door Actuator - Left
- M6R Air Temperature Door Actuator - Right
If the DTC sets
Replace the component that was connected immediately before the DTC set.
If the DTC does not set
- All OK.
DTC B0223, B022A, B0233, B0408 or B0418
- Ignition OFF, disconnect the harness connector at the appropriate door
actuator, ignition ON.
- Verify a test lamp flashes when connected between the 12 V reference
circuit terminal 2 and ground.
If the test lamp does not flash
- Ignition OFF, remove the test lamp and disconnect the harness connector
at the K33 HVAC
Control Module.
- Test for less than 2 ohms in the 12 V control circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If the test lamp flashes
- Connect a test lamp between each control circuit listed below and B+.
- Control Circuit - terminal 1
- Control Circuit - terminal 3
- Control Circuit - terminal 4
- Control Circuit - terminal 6
- Command the appropriate door actuator in both directions.
- Verify the test lamp turns ON and then OFF during at least one of the
directional commands
If the test lamp is always ON
- Ignition OFF, remove the test lamp and disconnect the harness connector
at the K33 HVAC
Control Module.
- Test for infinite resistance between the control circuit and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K33 HVAC Control Module.
If the test lamp is always OFF
- Ignition OFF, remove the test lamp and disconnect the harness connector
at the K33 HVAC
Control Module, ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Ignition OFF
- Test for less than 2 ohms in the control circuit end to end.
- If 2 ohms or greater, repair the open/high resistance is the circuit.
- If less than 2 ohms, replace the K33 HVAC Control Module.
If the test lamp turns ON and then OFF
- Replace the door actuator.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- HVAC Component Replacement Reference
- Control Module References for HVAC control module replacement,
programming and setup
DTC P0532 OR P0533: Air conditioning (a/c) refrigerant
pressure sensor
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of the diagnostic
category.
DTC Descriptors
DTC P0532
Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage
DTC P0533
Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The engine control module (ECM) monitors the high side refrigerant pressure
through the A/C refrigerant
pressure sensor. The ECM supplies a 5 V reference and a low reference to the
sensor. Changes in the A/C
refrigerant pressure cause the sensor signal to the ECM to vary. When the
pressure is high, the signal voltage is
high. When the pressure is low, the signal voltage is low. The ECM may use this
information to turn the cooling
fans on as well as to monitor clutch engagement. The HVAC module will receive
the A/C refrigerant pressure
information from the ECM via serial data.
Conditions for Running the DTC
- Engine is running.
- Any of the conditions for setting the DTC are met for 15 s.
- Battery voltage is between 11-18 V.
Conditions for Setting the DTC
P0532
The ECM detects that the A/C pressure is less than 1 psi (0.25 V).
P0533
The ECM detects that the A/C pressure is more than 428 psi (4.92 V).
Action Taken When the DTC Sets
- The A/C compressor is disabled.
- The ECM will illuminate the malfunction indicator lamp (MIL).
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Diagnostic Aids
A malfunction within the refrigerant system causing high pressure can cause
this DTC to set.
Reference Information
Schematic Reference
HVAC Schematics (Encore)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - Encore
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) ,
Powertrain Diagnostic Trouble
Code (DTC) Type Definitions (2H0)
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON
- Verify the scan tool engine control module A/C High Side Pressure
Sensor parameter is between 6.8 kPa
(1 psi) and 2950 kPa (428 psi).
- If not between 6.8 kPa (1 psi) and 2950 kPa (428 psi)
Refer to Circuit/System Testing
If between 6.8 kPa (1 psi) and 2950 kPa (428 psi)
- All OK
Circuit/System Testing
- Ignition OFF and all vehicle systems OFF, disconnect the harness
connector at the B1 A/C Refrigerant
Pressure Sensor. It may take up to 2 min for all vehicle systems to power
down.
- Test for less than 10 ohms between the low reference circuit terminal 1
and ground.
If 10 ohms or greater
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module.
- Test for less than 2 ohms in the low reference circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K20 Engine Control Module.
If less than 10 ohms
- Ignition ON.
- Test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and
ground.
If less than 4.8 V
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module.
- Test for infinite resistance between the 5 V reference circuit and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance
- Test for less than 2 ohms in the 5 V reference circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K20 Engine Control Module.
If greater than 5.2 V
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module, ignition ON.
- Test for less than 1 V between the 5 V reference circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
If between 4.8-5.2 V
- Verify the scan tool A/C High Side Pressure Sensor parameter is less
than .25 V.
If .25 V or greater
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module, ignition ON.
- Test for less than 1 V between the signal circuit terminal 3 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
If less than .25 V
- Install a 3 A fused jumper wire between the signal circuit terminal 3
and the 5 V reference circuit
terminal 2.
- Verify the scan tool A/C High Side Pressure Sensor parameter is greater
than 4.8 V.
If 4.8 V or less
- Ignition OFF, remove the jumper wire, disconnect the harness connector
at the K20 Engine Control
Module.
- Test for infinite resistance between the signal circuit terminal 3 and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance
- Test for less than 2 ohms in the signal circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, replace the K20 Engine Control Module.
If greater than 4.8 V
- Test or replace the B1 A/C Refrigerant Pressure Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- HVAC Component Replacement Reference
- Control Module References for engine control module replacement,
programming and setup
DTC P0645, P0646, OR P0647: Air conditioning (A/C)
compressor clutch relay
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptors
DTC P0645
Air Conditioning (A/C) Compressor Clutch Relay Control Circuit
DTC P0646
Air Conditioning (A/C) Compressor Clutch Relay Control Circuit Low Voltage
DTC P0646
Air Conditioning (A/C) Compressor Clutch Relay Control Circuit Low Voltage
DTC P0647
Air Conditioning (A/C) Compressor Clutch Relay Control Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
When the A/C switch is pressed, the HVAC control module sends a serial data
message to the engine control
module (ECM) indicating the A/C request. In response to this message, the ECM
grounds the A/C compressor
clutch relay control circuit energizing the A/C compressor clutch relay. With
the relay contacts closed, battery
voltage is applied through the A/C compressor clutch control circuit activating
the A/C compressor clutch
Conditions for Running the DTC
- The ignition voltage is between 11-18 volts.
- The engine speed is greater than 600 RPM.
- An A/C request is made.
Conditions for Setting the DTC
P0645 or P0646
The ECM detects a short to ground or an open at the A/C compressor clutch
relay control circuit.
P0647
The ECM detects a short to voltage at the A/C compressor clutch relay control
circuit.
Action Taken When the DTC Sets
P0645 or P0646
The A/C compressor is inoperative or always active
P0647
The A/C compressor is inoperative.
Conditions for Clearing the DTC
A history DTC clears after 40 consecutive warm-up cycles have occurred
without a malfunction.
Reference Information
Schematic Reference
HVAC Schematics (Encore)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - Encore
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) ,
Powertrain Diagnostic Trouble
Code (DTC) Type Definitions (2H0)
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, and all vehicle systems OFF. Disconnect the harness
connector at the Q2 A/C Compressor
Clutch. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 10 ohms between the Q2 A/C Compressor Clutch ground
circuit terminal A and ground.
If 10 ohms or greater
- Ignition OFF.
- Test for less than 2 ohms in the ground circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, repair the open/high resistance in the ground
connection.
If less than 10 ohms
- Connect a test lamp between the control circuit terminal B and ground,
ignition ON.
- Verify the test lamp does not turn ON and OFF when commanding the Q2 A/C
Compressor Clutch On and Off with a scan tool.
If the test lamp turns ON and OFF
Test or replace the Q2 A/C Compressor Clutch
If the test lamp does not turn ON and OFF
- Ignition OFF, connect the harness connector at the Q2 A/C Compressor
Clutch. Disconnect the X3
harness connector at the X50A Fuse Block - Underhood, ignition ON.
- Verify the Q2 A/C Compressor Clutch is not activated.
If the Q2 A/C Compressor Clutch is activated
- Ignition OFF, disconnect the harness connector at the Q2 A/C Compressor
Clutch, ignition ON.
- Test for less than 1 V between the control circuit terminal B and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, test or replace the Q2 A/C Compressor Clutch.
If the Q2 A/C Compressor Clutch is not activated
- Connect a 10 A fused jumper wire between the control circuit terminal B5
and B+.
- Verify the Q2 A/C Compressor Clutch activates.
If the Q2 A/C Compressor Clutch does not activate
- Ignition OFF, remove the jumper wire, disconnect the harness connector
at the Q2 A/C Compressor
Clutch, ignition ON.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance
- Test for less than 2 ohms in the control circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, test or replace the Q2 A/C Compressor Clutch.
If the Q2 A/C Compressor Clutch activates
- Ignition OFF, connect the X3 harness connector at the X50A Fuse Block -
Underhood and disconnect the
harness connector at the K20 Engine Control Module, ignition ON.
- Verify the Q2 A/C Compressor Clutch is not activated.
If the Q2 A/C Compressor Clutch is activated
- Ignition OFF, disconnect the X3 harness connector at the X50A Fuse Block
- Underhood.
- Test for infinite resistance between the X3 X50A Fuse Block - Underhood
control circuit terminal
B4 and ground.
- If less than Infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, test or replace the X50A Fuse Block - Underhood.
If the Q2 A/C Compressor Clutch is not activated
- Connect a 3 A fused jumper wire between the K20 Engine Control Module
control circuit terminal for the
KR29 A/C Compressor Clutch Relay and ground.
- Verify the Q2 A/C Compressor Clutch activates.
If the Q2 A/C Compressor Clutch does not activate
- Ignition OFF, remove the jumper wire, disconnect the X3 harness
connector at the X50A Fuse
Block - Underhood, ignition ON.
- Test for less than 1 V between the X3 X50A Fuse Block - Underhood
control circuit terminal B4
and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Test for less than 2 ohms in the control circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms, test or replace the X50A Fuse Block - Underhood.
If the Q2 A/C Compressor Clutch activates
- Replace the K20 Engine Control Module.
Component Testing
Compressor Clutch Test
- Ignition OFF, disconnect the Q2 A/C Compressor Clutch.
- Test for 3.9 - 4.3 ohms between terminals A and B
If not between 3.9 - 4.3 ohms
Replace the Q2 A/C Compressor Clutch.
If between 3.9 - 4.3 ohms
- All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- HVAC Component Replacement Reference
- Front Compartment Fuse Block Replacement
- Control Module References for engine control module replacement,
programming and setup
Symptoms - HVAC systems - automatic
NOTE: The following steps must be completed before using the
symptom tables:
- Perform the Diagnostic System Check - Vehicle before using the HVAC
System Malfunction procedure
in order to verify that all of the following are true:
- There are no DTCs set.
- The control modules can communicate via the serial data link.
- Review the system operation in order to familiarize yourself with the
system functions. Refer to
Automatic HVAC Description and Operation.
Visual/Physical Inspection
NOTE: Shutting one or more outlets may adversely affect the
Automatic HVAC
system by producing erroneous duct air temperature sensor readings in
the duct connecting to the closed outlet. Where possible, always operate
the Automatic HVAC system with all outlets open.
- Inspect for aftermarket devices which may affect the operation of the
HVAC System. Refer to Checking
Aftermarket Accessories .
- Inspect the easily accessible or visible system components for obvious
damage or conditions which may
cause the symptom.
- Verify the A/C compressor turns freely and is not seized.
- Verify that the customer is using the correct key to enable
personalization and is not inadvertently
activating auxiliary HVAC controls.
- The A/C compressor will not operate in cold outside air temperatures.
- The following conditions may cause window fogging:
- Wet carpet or mats
- High humidity
- Interior water leak
- Blocked A/C evaporator drain tube
- Maximum passenger capacity
- Blocked body pressure relief valves
- Inspect the air distribution system for causes of reduced air flow:
- Obstructed or dirty passenger compartment air filter, if equipped
- Blocked or damaged air inlet or outlet vents
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent
conditions. Refer to Testing for
Intermittent Conditions and Poor Connections .
Symptom List
Refer to HVAC System Malfunction in order to diagnose the symptom.
HVAC System malfunction
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
Diagnostic Aids
Check the following mechanical fault sources:
- Air distribution box
- Air distribution hoses/air distribution ducts
Reference Information
Schematic Reference
HVAC Schematics (Encore)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - Encore
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
J43600 Air Conditioning Service Center
Circuit/System Verification
NOTE: Check for bulletins before proceeding.
- Ignition ON.
- Verify every applicable scan tool Switch parameter changes when pressing
the appropriate switch on the
A26 HVAC Controls.
If any parameter does not change
Replace the A26 HVAC Controls.
If all parameters change
- Verify the blower motor operates properly with the blower motor switch
in each speed position.
If the blower motor does not operate in each speed position
Refer to DTC B0193.
If the blower motor operates properly in each speed position
- Verify the HVAC doors listed below move when pressing the appropriate
switch.
- Driver Temperature
- Passenger Temperature
- Mode
- Recirculation
If any HVAC door does not move
Refer to DTC B0223, B022A, B0233, B023A, B0408, or B0418.
If all HVAC doors move
- Install the J43600 Air Conditioning Service Center.
- Verify the high side pressure reading on the Air Conditioning Service
Center is within 10% of the scan
tool ECM A/C High Side Pressure Sensor parameter
If the reading is not within 10%
Refer to DTC P0532 or P0533.
If the reading is within 10%
- Verify the A/C High Side Pressure Sensor parameter is between 269-2929
kPa (39-425 PSI).
If the reading is not between 269-2929 kPa (39-425 PSI)
Refer to Air Conditioning (A/C) System Performance Test .
If the reading is between 269-2929 kPa (39-425 PSI)
- Verify the scan tool parameters listed below are within 10% of ambient
temperature.
- Lower Left Duct Air Temperature Sensor
- Upper Left Duct Air Temperature Sensor
- Lower Right Duct Air Temperature Sensor
- Upper Right Duct Air Temperature Sensor
- A/C Evaporator Temperature Sensor
If not within 10% of ambient temperature
Refer to DTC B0173, B0178, B0509, B0514 or B3933.
If within 10% of ambient temperature
- Verify the scan tool parameters listed below are within 10% of actual
conditions.
- Passenger Compartment Humidity
- Passenger Compartment Humidity Sensor Temperature
- Passenger Compartment Windshield Temperature
If not within 10% of actual conditions
Refer to DTC B018A, B048C, B048F, or B1395.
If within 10% of actual conditions
- Engine ON, A/C system ON.
- Verify cool air flows from the ducts with the temperature control in the
coldest position.
If the air is not cool
- Verify the Q2 A/C Compressor Clutch is engaged.
- If the Q2 A/C Compressor Clutch is not engaged, refer to Air
Conditioning Compressor
Malfunction.
- If the Q2 A/C Compressor Clutch is engaged, refer to Air Conditioning
(A/C) System
Performance Test .
If the air is cool
- Verify warm air flows from the ducts with the temperature control in the
warmest position.
If the air is not warm
Refer to Heating Performance Diagnostic .
If the air is warm
- Engine OFF, ignition ON.
- Verify the Sunload parameter changes while covering the B10B Ambient
Light/Sunload Sensor with a
shop towel and changes when shining a bright light on it.
If the Sunload parameter does not change
Refer to DTC B0163, B0183, or B1405.
If the Sunload parameter changes
- Verify the actual inside air temperature, using a thermometer, is less
than 3ºC (5ºF) difference from the
scan tool Inside Passenger Compartment Air Temp. Sensor parameter.
If greater than a 3ºC (5ºF) difference
Refer to DTC B0163, B0183, or B1405.
If less than a 3ºC (5ºF) difference
- All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- HVAC Component Replacement Reference
- Control Module References for HVAC control module replacement,
programming and setup
Air conditioning compressor malfunction
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
Circuit/System Description
The A/C compressor uses a conventional belt driven magnetic clutch to engage
and mechanically turn the
compressor. When the A/C switch is pressed, the HVAC control module sends an A/C
request message to the
ECM via serial data. If specific criteria is met, the ECM then grounds the A/C
compressor clutch relay control
circuit, which will switch the A/C compressor clutch relay. With the relay
contacts closed, battery voltage is
supplied to the permanently grounded A/C compressor clutch. The A/C compressor
clutch will then be
activated.
Diagnostic Aids
The following conditions must be met in order to turn on the A/C compressor:
- Battery voltage is between 9-18 V.
- Engine coolant temperature is less than 124ºC (255ºF).
- Engine speed is greater than 600 RPM.
- Engine speed is less than 5 500 RPM.
- A/C high side pressure is between 269-2 929 kPa (39-425 PSI).
- Throttle position is less than 100%.
- Evaporator temperature is greater than 3ºC (38ºF).
- ECM does not detect excessive torque load.
- ECM does not detect insufficient idle quality.
- The ambient temperature is above 1ºC (34ºF).
- Blower motor ON
Reference Information
Schematic Reference
HVAC Schematics (Encore)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - Encore
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
NOTE: Refer to HVAC System Malfunction before performing this
procedure.
- Ignition ON, press and release the A/C Switch.
- Verify the HVAC control module scan tool A/C Switch parameter changes
between Active and Inactive.
If the parameter does not change
Replace the A26 HVAC Controls.
If the parameter changes
- Set A/C system to coolest setting with blower ON.
- Press and release the A/C switch several times.
- Verify the engine control module (ECM) scan tool A/C Request Signal
parameter changes between
Active and Inactive.
If the parameter does not change
Replace the K33 HVAC Control Module.
If the parameter changes
- Verify the A/C compressor clutch engages when commanding the engine
control module (ECM) A/C
Relay output function On and Off with a scan tool.
If the A/C compressor clutch does not engage
Refer to DTC P0645, P0646, or P0647
If the A/C compressor clutch engages
- All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- HVAC Component Replacement Reference
- Control Module References for HVAC control module replacement,
programming and setup
Actuator recalibration
HVAC Control Module Replacement
When replacing or disconnecting the HVAC control module, it will be necessary
to perform a recalibration
process. When installing or reconnecting the HVAC control module, be sure to
perform the following:
Preferred Method (with Scan Tool)
NOTE: Do not adjust any controls on the HVAC control module while
the HVAC control
module is self-calibrating. If interrupted, improper HVAC performance will
result.
- Ignition OFF.
- Disconnect the scan tool.
- Install/connect the HVAC control module.
- Connect all previously disconnected components.
- Start the vehicle.
- With the scan tool, initiate the HVAC Actuators Learn feature of the
HVAC control module Special Functions menu.
- Operate system and verify that no DTCs have set as current DTCs.
- If DTC B101E 4B is set after attempting the actuator recalibration
procedure, perform the following:
- Verify which actuator does not have a scan tool learn status parameter
status of complete.
- Verify the unlearned actuator is physically rotating - A common cause of
DTC B101E 4B is an
actuator that is electrically OK but fails to physically rotate (e.g.
stripped gears).
- If the unlearned actuator is not physically rotating, replace the
actuator, otherwise replace the
HVAC control module.
Alternate Method (without Scan Tool)
NOTE: Do not adjust any controls on the HVAC control module while
the HVAC
control module is self-calibrating. If interrupted, improper HVAC
performance will result.
- Clear all DTCs.
- Ignition OFF.
- Install/connect the HVAC control module.
- Connect all previously disconnected components.
- Remove the HVAC control module fuse for a minimum of 10 s.
- Install the HVAC control module fuse.
- Start the vehicle.
- Wait 40 s for the HVAC control module to self-calibrate.
Actuator Replacement
When replacing an HVAC actuator it will be necessary to allow the HVAC
control module to perform a
recalibration process. When installing an HVAC actuator be sure to perform one
of the following:
Preferred Method (with Scan Tool)
NOTE: Do not adjust any controls on the HVAC control module while
the HVAC
control module is self-calibrating. If interrupted, improper HVAC
performance will result.
- Clear all DTCs.
- Ignition OFF.
- Install the HVAC actuator.
- Connect all previously disconnected components.
- Start the vehicle.
- With the scan tool, initiate the HVAC Actuators Relearn feature of the
HVAC control module Special
Functions menu.
- Operate system and verify that no DTCs have set as current DTCs.
- If DTC B101E 4B is set after attempting the actuator recalibration
procedure, perform the following:
- Verify which actuator does not have a scan tool learn status parameter
status of complete.
- Verify the unlearned actuator is physically rotating - A common cause of
DTC B101E 4B is an
actuator that is electrically OK but fails to physically rotate (e.g.
stripped gears).
- If the unlearned actuator is not physically rotating, replace the
actuator, otherwise replace the
HVAC control module.
Alternate Method (without Scan Tool)
NOTE: Do not adjust any controls on the HVAC control module while
the HVAC
control module is self-calibrating. If interrupted, improper HVAC
performance will result
- Clear all DTCs.
- Ignition OFF.
- Install the HVAC actuator.
- Connect all previously disconnected components.
- Remove the HVAC control module fuse for a minimum of 10 s.
- Install the HVAC control module fuse.
- Start the vehicle.
- Wait 40 s for the HVAC control module to self-calibrate.
READ NEXT:
Heater and air conditioning control replacement
Fig. 6: Heater And Air Conditioning Control
Heater and Air Conditioning Control Replacement
HEATER AND AIR CONDITIONING REMOTE CONTROL REPLACEMENT
AUTOMATIC HVAC DESCRIPTION AND OPERATION
The air temperature and the air delivery description and operation are
divided into five areas:
HVAC Control Components
Air Speed
Air Delivery
Heating an
SEE MORE:
SCHEMATIC WIRING DIAGRAMS
DRIVER SEAT WIRING SCHEMATICS (ENCORE)
Power Seat (Without AAG) and Lumbar
Fig. 1: Power Seat (Without AAG) and Lumbar
Module Power, Ground, Serial Data, and Memory Controls (AAG)
Fig. 2: Module Power, Ground, Serial Data, and Memory Controls (AAG)
Seat Adjuster Switch
The following is an overview of instructions for the general information and
13 step System Verification
included in the Diagnostic System Check - Vehicle procedure.
Diagnostic Instructions
A link to Strategy Based Diagnosis is provided as an overview on how a
technician should diagnose a vehicle.