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Trunk Release Inoperative



Trunk Release Inoperative

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 interior rear compartment lid release switch receives a signal from the driver door switch assembly (DDSA). When the interior rear compartment lid release switch is activated the signal circuit is pulled to ground. The DDSA interprets this and sends a GMLAN serial data message to the RIM requesting the rear compartment lid be released. The rear integration module (RIM) grounds the trunk release relay control circuit which energizes the TRK DR REL relay. The trunk release relay is supplied with battery voltage at all times. With the relay coil energized, the relay switch contacts close allowing battery voltage to flow to the rear compartment lid release actuator causing the rear compartment lid to release. The rear compartment lid release actuator is permanently grounded at G402. When the rear compartment lid release actuator releases the rear compartment lid, the rear compartment lid ajar switch, which is internal the rear compartment lid release actuator, is supplied with ground which causes the trunk ajar switch signal circuit to be pulled low. The trunk ajar switch signal circuit is an input to the RIM. When the RIM receives a trunk ajar signal, a GMLAN serial data message is sent to the instrument panel cluster (IPC) requesting the TRUNK OPEN message be displayed on the message center.


The exterior rear compartment lid release switch receives a signal from the remote control door lock receiver (RCDLR). When the exterior rear compartment lid release switch is activated the signal circuit is pulled to ground. The RCDLR interprets this and sends a GMLAN serial data message to the RIM requesting the rear compartment lid be released. The rear integration module (RIM) grounds the trunk release relay control circuit which energizes the TRK DR REL relay. The trunk release relay is supplied with battery voltage at all times. With the relay coil energized, the relay switch contacts close allowing battery voltage to flow to the rear compartment lid release actuator causing the rear compartment lid to release. The rear compartment lid release actuator is permanently grounded at G402.


Reference Information
Schematic Reference

* Remote Function Schematics ([1][2]Electrical Diagrams)
* Release Systems Schematics (Release Systems Schematics)

Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

* Keyless Entry System Description and Operation (Description and Operation)
* Luggage Compartment Description and Operation (Description and Operation)

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

1. Ignition ON, observe the scan tool trunk release switch parameter located in the driver door switch menu while activating the interior rear compartment lid release switch ON and OFF. The reading should toggle between ACTIVE and INACTIVE.

• If the readings do not change as the switch is activated, refer to Trunk Release Switch Malfunction - Interior.

2. Ignition ON, observe the scan tool trunk release switch parameter located in the remote control door lock receiver (RCDLR) menu while activating the exterior rear compartment lid release switch ON and OFF. The reading should toggle between ACTIVE and INACTIVE.

• If the readings do not change as the switch is activated, refer to Trunk Release Switch Malfunction - Exterior.

3. Ignition ON, observe the scan tool valet switch parameter located in the instrument panel module (IPM) menu while activating the valet switch ON and OFF. The reading should toggle between ACTIVE and INACTIVE.

• If the readings do not change as the switch is activated, refer to Valet Switch Malfunction.




Circuit/System Testing


Trunk Release Switch Malfunction - Interior
1. Ignition OFF, disconnect the harness connector at the interior rear compartment lid release switch.
2. Ignition OFF, scan tool OFF, test for less than 10.0 ohms between the ground circuit terminal 1 and ground.

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

3. Ignition ON, verify the scan tool trunk release switch parameter located in the driver door switch menu is INACTIVE.

• If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the DDSA.

4. Install a 3A fused jumper wire between the signal circuit terminal 3 and ground. Verify the scan tool trunk release switch 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 DDSA.

5. If the circuits test normal, test or replace the interior rear compartment lid release switch.



Trunk Release Switch Malfunction - Exterior
1. Ignition OFF, disconnect the harness connector at the exterior rear compartment lid release switch.
2. Test for less than 5.0 ohms between the ground circuit terminal C and ground.

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

3. Ignition ON, verify the scan tool trunk release switch parameter located in the remote control door lock receiver (RCDLR) menu parameter is INACTIVE.

• If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the remote control door lock receiver (RCDLR).

4. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool scan tool trunk release switch 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 remote control door lock receiver (RCDLR).

5. If all circuits test normal, test or replace the exterior rear compartment lid release switch.



Valet Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the valet switch.
2. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal A and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition ON, verify the scan tool valet switch parameter is INACTIVE.

• If not the specified value, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the IPM.

4. Install a 3A fused jumper wire between the signal circuit terminal B and the B+ circuit terminal A. Verify the scan tool valet switch parameter is ACTIVE.

• If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the IPM.

5. If all circuits test normal, test or replace the valet switch.



Trunk Release Malfunction
1. Ignition OFF, disconnect the trunk release relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal R33 and ground.

• If the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify that a test lamp illuminates between the relay switch B+ circuit terminal R32 and ground.

• If the test lamp does not illuminate, test the relay switch B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the relay switch B+ circuit fuse is open, test the relay controlled output circuit terminal R33 for a short to ground.

4. Ignition ON, verify that a test lamp illuminates between the relay coil B+ circuit terminal R31 and ground.

• If the test lamp does not illuminate, test the relay coil B+ circuit for a short to ground or an open/high resistance.

5. Ignition OFF, disconnect the harness connector at the rear compartment lid release actuator.
6. Ignition OFF, all doors closed, test for less than 5.0 ohms between the rear compartment lid release actuator ground circuit terminal B and ground.

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

7. Connect the harness connector at the rear compartment lid release actuator.
8. Ignition ON, connect a 40A fused jumper wire between the B+ circuit terminal R32 and the control circuit terminal R33. Verify the rear compartment lid release actuator is activated.

• If the rear compartment lid release actuator does not activate, test the control circuit terminal R33 for an open/high resistance. If the circuit tests normal, test or replace the rear compartment lid release actuator.

9. Ignition OFF, connect a test lamp between the relay B+ circuit terminal R31 and the relay control circuit terminal R35.
10. Command the trunk release relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the RIM.


• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the RIM.

11. If all circuits test normal, test or replace the trunk release relay.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Rear Compartment Lid Switch Replacement (Exterior) (Service and Repair)
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Rear Compartment Lid Valet Lock Out Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for DDSA, RCDLR, or RIM replacement, setup, and programming




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