Door ajar indicator description and operation
Door Ajar Indicator System Components
The door ajar indicator system consists of the following components:
Door Ajar Indicator GG SUV Block Diagram
Fig. 41: Door Ajar Indicator GG SUV Block Diagram
Driver, Passenger and Rear Door Ajar (AXG, AEF, AER)
The window motors provide a 12V signal to the respective door ajar switch within the door latch to indicate the status of the door. When the door is open, the contract within the ajar switch closes providing a ground part for the signal circuit. The window motor will detect the voltage drop in the ajar signal circuit and will send a serial data message to the body control module. The body control module will then send a message to the instrument cluster which will illuminate the door ajar icon.
Passenger and Rear Doors Ajar (AER, AEQ)
The passenger and rear window switches provide a 12V signal to the respective door ajar switch within the door latch to indicate the status of the door. When the door is open, the contract within the ajar switch closes providing a ground part for the signal circuit. The window switch will detect the voltage drop in the ajar signal circuit and will send a serial data message to the body control module. The body control module will then send a message to the instrument cluster which will illuminate the door ajar icon.
Driver, Passenger and Rear Doors Ajar (With A55, A66, A33 or APW)
The body control module provides a 12V signal to each door ajar switch within the door latch to indicate the status of the door. When the door is open, the contract within the ajar switch closes providing a ground part for the signal circuit. The body control module will detect the voltage drop in the ajar signal circuit and will send a message to the instrument cluster which will illuminate the door ajar icon
Liftgate Ajar
The body control module provides a 12 V signal to the liftgate ajar signal circuit. The liftgate latch contains an ajar switch which is normally open when the liftgate is closed. When the liftgate is opened, the normally open ajar switch closes. With the ajar switch closed, ground is provided to the ajar switch signal circuit. The body control module detects the voltage drop and sends a serial data message to the instrument panel to display the door ajar indicator
FUEL FILL DOOR DESCRIPTION AND OPERATION (NO8 ONLY)
Fuel Door Unlatch System Components
The locking and unlocking of the fuel door is a function of the power door lock system. The fuel door unlatch actuator shares the circuit with the driver door latch. The body control module (BCM), upon receipt of a lock switch lock or unlock signal, will switch the appropriate door latch, as well as a fuel filler door unlatch actuator control circuits to B+ voltage. The opposing side of the door latch and fuel filler door unlatch actuator is connected to ground provided by the BCM through the other the door latch control circuits, along with the fuel filler door unlatch actuator, will lock or unlock as commanded.
Power door locks description and operation
Door Lock System Components
The power door lock system consists of the following components:
Power Door Locks Block Diagram
Fig. 42: Power Door Locks Block Diagram
Door Lock System Controls
The power door lock system can be controlled by any of the following:
Door Lock Operation
When the central door lock switch is activated in the lock or unlock position the BCM will receive a ground signal on either the door lock switch lock or unlock signal circuits.
The BCM, upon receipt of a lock switch lock or unlock signal, will supply voltage to the door lock actuator lock or unlock control circuits. Since the opposite side of the lock actuator is connected to ground through the other lock actuator control circuit, the doors will then lock or unlock as commanded.
The following three circuits are used to operate the lock:
Power Door Child Lock Block Diagram
Fig. 43: Power Door Child Lock Block Diagram
Child Door Lockout Operation
The operator has the option to disable the interior rear door handles to prevent the unauthorized opening of the rear door doors while still retaining normal rear exterior door handle functions. When the child door lockout switch is pressed, the BCM will energize the door lock security relay, send a 12V pulse to the rear door latches activating the lockout feature and will command the child lockout indicator to illuminate. The rear door plungers will still function normally by pressing the central door lock switch but the child lockout latches will disable the interior rear door handles. Pressing the child lockout switch again will signal a command to the BCM which will de-energize the door lock security relay, send a 12V pulse to the rear door latches to de-active the lockout feature and restore normal interior rear door handle functions and the turn off the child lockout indicator.
The rear door latches contain switches that are open when the rear doors are not locked out and closed when the rear doors are locked out which is monitored by the BCM to determine the lockout status of rear door latches
If the child lockout indicator flashes while trying to lockout the rear door handles indicates that there is a fault detected in the child lockout system and one or both interior rear door handles may not be disabled.
Rear hatch/gate description and operation
Liftgate Release System Components
Liftgate Release Block Diagram
Fig. 44: Liftgate Release Block Diagram
Liftgate Release Operation
Liftgate Unlatch Switch
The BCM monitors supplies a 12 V signal to the liftgate unlatch switch so that when the switch is pressed, the voltage within the signal circuit is pulled low and in response, the BCM will detect the voltage drop and check the status of the door lock system. If the doors are locked, the BCM will ignore the request, if the All Doors Unlock has been commanded, the BCM will recognize the request and will provide voltage to the release relay.
Liftgate Latch Assembly
When BCM receives a liftgate release command from the liftgate unlatch switch, the BCM applies brief pulse of voltage to the liftgate unlatch relay control circuit, which energizes the coil side of the relay. The switch side of the liftgate unlatch relay then momentarily closes, supplying a brief pulse of battery positive voltage to the liftgate latch assembly. The liftgate latch assembly is continuously grounded and when it receives the voltage pulse, it will become energized and the latch will activate releasing the liftgate so that it may be manually raised to an open position.
Keyless Entry Transmitter
All doors of the vehicle must first be commanded to UNLOCK prior to pressing the liftgate unlatch switch. The BCM monitors the status of the vehicle door latches. If the passenger doors are locked, the BCM will ignore the signal from the liftgate unlatch switch. Pressing the appropriate button on the keyless entry transmitter will send a request to the remote control door lock receiver which will in turn send a serial data message to unlock all doors.