Liftgate/Liftgate Window Ajar Indicator Malfunction

LIFTGATE/LIFTGATE WINDOW AJAR INDICATOR MALFUNCTION

DIAGNOSTIC FAULT INFORMATION
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

CIRCUIT/SYSTEM DESCRIPTION
The body control module (BCM) receives an input from both the liftgate and liftglass ajar switches. The ajar switches are normally open when the liftgate and the liftglass are fully closed. When either the liftgate or liftglass is opened, the appropriate ajar switch contacts close providing a path to ground. The driver information center (DIC) located at the bottom of the instrument panel cluster (IPC), illuminates the rear access open message when either the glass or the gate is open. The IPC receives a GMLAN serial data message from the BCM indicating the liftgate or liftglass ajar status. If this message is displayed and the vehicle speed is greater than 8.1 km/h (5 mph), a chime will sound.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect both the liftgate and liftglass ajar switches.
2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit and ground.
- If greater than 1 ohm, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Liftgate Ajar Switch parameter is Inactive.
- If not Inactive, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM.
4. Ignition ON, check to see that the rear access open message is not displayed.
- If the message is displayed in the DIC, replace the IPC.
5. Ignition ON, install a 3-amp fused jumper wire between the signal circuit and ground. Verify the scan tool Liftgate Ajar Switch parameter is Active.
- If not Active, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal replace the BCM.
6. Ignition ON, check to see that the rear access open message is displayed.
- If the message is not displayed in the DIC, replace the IPC.
7. If all circuits test normal, test or replace the liftgate ajar switch or the liftglass ajar switch.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Control Module References for BCM and IPC replacement, setup, and programming. Programming and Relearning