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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 module (DDM). When the interior rear compartment lid release switch is activated, the signal circuit is pulled to ground. The DDM interprets this and sends a serial data message to the body control module (BCM) requesting the rear compartment lid be released. The BCM responds by applying battery voltage to the trunk release relay control circuit which energizes the TRUNK/RELSE 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 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 serial data message to the BCM requesting the rear compartment lid be released. The BCM responds by applying battery voltage to the trunk release relay control circuit which energizes the TRUNK/RELSE 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.

Reference Information
Schematic Reference

Release Systems Schematics (Release Systems Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
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, command the Trunk Release with a scan tool. The rear compartment lid latch should release the trunk lid.

• If the rear compartment lid latch is inoperative, refer to Rear Compartment Lid Malfunction.

2. Command the trunk release by using the interior trunk release switch. The rear compartment lid latch should release the trunk lid.

• If the rear compartment lid latch does not release, refer to Interior Trunk Release Switch Malfunction.

3. Command the trunk release by using the exterior rear compartment lid release switch. The rear compartment lid latch should release the trunk lid.

• If the rear compartment lid latch does not release, refer to Exterior Trunk Release Switch Malfunction.

Circuit/System Testing

Rear Compartment Lid Release Malfunction
1. Ignition OFF, disconnect the TRUNK/RELSE relay.
2. Test for less than 5 ohms between the ground circuit terminal 85 and ground.

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

3. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 30 and ground.

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

4. Verify that a test lamp illuminates between the B+ circuit terminal 87 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the TRUNK/RELSE fuse is open, test the control circuit terminal 30 for a short to ground.

5. Ignition OFF, disconnect the harness connector at the rear compartment lid latch.
6. Test for less than 1 ohm between the 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 latch.
8. Ignition ON, connect a 15A fused jumper wire between the B+ circuit terminal 87 and the control circuit terminal 30. Verify the rear compartment lid latch is activated.

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

9. Connect a test lamp between the control circuit terminal 86 and ground.
10. Command the trunk release 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 voltage. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

11. If all circuits test normal, test or replace the TRUNK/RELSE relay.

Interior Trunk Release Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the interior rear compartment lid release switch.
2. Test for less than 25 ohms between the low reference circuit terminal A and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance, if the circuit tests normal, replace the DDM.

3. Ignition ON, test for greater than 9 volts between the signal circuit terminal C and ground.

• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the DDM.

4. Connect a 3A fused jumper wire between the signal circuit terminal C and ground, verify the rear compartment lid latch releases the trunk lid.

• If the rear compartment lid latch is inoperative, test the signal circuit for a short to voltage. If the circuit tests normal, replace the DDM.

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

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

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

3. Connect the harness connector at the exterior rear compartment lid release switch and disconnect the X1 harness connector at the RCDLR.
4. Connect a test lamp between the signal circuit terminal P and B+.
5. Ignition ON, command the trunk release ON and OFF by pressing and releasing the exterior rear compartment lid release switch. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the signal circuit for a short to ground. If the circuit tests normal, replace the exterior rear compartment lid release switch.

• If the test lamp is always OFF, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the exterior rear compartment lid release switch.

6. If all circuits test normal, replace the RCDLR.

Component Testing

Rear Compartment Lid Latch
1. Ignition OFF, disconnect the harness connector at the rear compartment lid latch.
2. Install a 15A fused jumper wire between the control terminal A and 12 volts. Install a jumper wire between the ground terminal B and ground. Verify the rear compartment lid latch activates.

• If the rear compartment lid latch does not perform as specified, replace the rear compartment lid latch.

Rear Compartment Lid Release Switch
1. Ignition OFF, disconnect the harness connector at the appropriate rear compartment lid release switch.
2. Test for infinite resistance between the signal terminal and the ground terminal listed below with the switch in the open position.

* Interior rear compartment lid release switch signal terminal C and low reference terminal A.
* Exterior rear compartment lid release switch signal terminal A and ground terminal C.

• If not the specified value, replace the rear compartment lid release switch.

3. Test for less than 2 ohms between the signal terminal and the ground terminal listed below with the switch in the closed position.

* Interior rear compartment lid release switch signal terminal C and low reference terminal A.
* Exterior rear compartment lid release switch signal terminal A and ground terminal C.

• If greater than the specified range, replace the rear compartment lid release switch.

Repair Instructions

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

* Rear Compartment Lid Release Switch Replacement (Service and Repair)
* Rear Compartment Lid Latch Replacement (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))
* Control Module References (Programming and Relearning) for BCM, DDM, or RCDLR replacement, setup, and programming

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