Liftgate/Liftgate Window Ajar Indicator Malfunction Manual Liftgate

The body control module (BCM) receives an input from the liftgate ajar assembly. The ajar assembly is normally open when the liftgate is fully closed. When the liftgate is opened, the ajar assembly contacts close providing a path to ground. The driver information center (DIC) illuminates the rear access open message when the gate is open. The instrument panel cluster (IPC) receives a serial data message from the BCM indicating the liftgate ajar status. If this message is displayed and the vehicle speed is greater than 8.1 km/h (5 mph), a chime will sound.

Important: Before testing can be performed the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power for the procedure.

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Displays and Gages Connector End Views

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

Ignition ON, verify that the scan tool Rear Closure Ajar parameter changes between Active and Inactive, while opening and closing the liftgate.

1. Ignition OFF, disconnect the harness connector at the liftgate latch assembly.
2. Test for less than 1 ohm of resistance between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Rear Closure Ajar parameter is Inactive.

⇒	If not the specified value, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal 6 and ground. Verify the scan tool Rear Closure Ajar parameter is Active.

⇒	If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal replace the BCM.

5. If all circuits test normal, test or replace the liftgate latch assembly.

1. Ignition OFF, disconnect the harness connector at the liftgate latch assembly.
2. Test for infinite resistance between the signal terminal 6 and the ground terminal 5 with the latch in the open position.

⇒	If not the specified value, replace the liftgate latch assembly.

3. Test for less than 1.0 ohms between the signal terminal 6 and the ground terminal 5 with the latch in the closed position.

⇒	If greater than the specified range, replace the liftgate latch assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming.

Liftgate/Liftgate Window Ajar Indicator Malfunction Power Liftgate

The driver information center (DIC) illuminates the LIFT GATE AJAR indicator when the liftgate module (LGM) detects the liftgate ratchet switch is closed to ground indicating the liftgate is open. The instrument panel cluster receives a GMLAN serial data message from the LGM indicating the liftgate ajar status. If this message is displayed and the vehicle speed is greater than 8 km/h (5 mph), a chime will sound.

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Displays and Gages Connector End Views

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

Ignition ON, observe the scan tool LGM Latch Ratchet Sw. parameter while opening and closing liftgate. The reading should change between Active and Inactive.

1. Ignition OFF, disconnect the harness connector at the liftgate latch assembly.
2. Ignition ON, verify the scan tool LGM Latch Ratchet Sw. parameter is Inactive.

⇒	If not the specified value, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the LGM.

3. If all circuits test normal, replace the liftgate latch assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for LGM replacement, setup, and programming