Liftgate Ajar Indicator Malfunction
Liftgate Ajar Indicator Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) receives an input from the liftgate ajar switch. The ajar switch is normally open when the liftgate is fully closed. When the liftgate is opened, the 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 ajar status. If this message is displayed and the vehicle speed is greater than 8.1 km/h (5 mph), a chime will sound.
Reference Information
Schematic Reference
Instrument Cluster Schematics (Instrument Cluster Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for Scan Tool Information
Circuit/System Verification
Ignition ON, observe the scan tool Liftgate Open Switch parameter while opening and closing the liftgate. The reading should change between Active and Inactive.
Circuit/System Testing
1. Ignition OFF, disconnect the liftgate door jamb switch.
2. Test for less than 1 ohm of resistance between the ground circuit terminal D and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Liftgate Open Switch parameter is Inactive.
• If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM.
4. Check to see that the liftgate open message is not displayed.
• If the message is displayed in the DIC, replace the IPC.
5. Install a 3-amp fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool Liftgate Open 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. Check to see that the liftgate 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 door jamb switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the liftgate door jamb switch.
2. Test for infinite resistance between the signal terminal and the voltage supply terminal with the switch in the open position.
• If less than infinite resistance, replace the liftgate door jamb switch.
3. Test for less than 1 ohms between the signal terminal and the voltage supply terminal with the switch in the closed position.
• If greater than the specified range, replace the liftgate door jamb switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for BCM and IPC replacement, setup, and programming