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Trunk Release Inoperative



TRUNK RELEASE INOPERATIVE

DIAGNOSTIC FAULT INFORMATION




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

CIRCUIT/SYSTEM DESCRIPTION
The rear compartment lid can be released by operating the rear compartment lid release switch or pressing the rear compartment release button on the key fob. The gear selector may be in any position, but vehicle speed must equal 0 for the rear compartment lid to release. When the rear compartment lid release switch is pushed, the rear compartment lid release signal circuit to the body control module (BCM) is grounded. When the rear compartment lid release signal circuit is grounded, the BCM grounds the coil side of the trunk release relay through the trunk release relay control circuit. With ground applied to the coil side of the trunk release relay, voltage is applied to the rear compartment lid release actuator, opening the rear compartment

CIRCUIT/SYSTEM VERIFICATION
1. Ignition ON, observe the scan tool Trunk Release switch parameter while pressing the Rear Compartment Lid Release Switch. The reading should change between Active and Inactive.
- If the reading does not change between Active and Inactive, refer to Rear Compartment Lid Switch Malfunction.
2. Command the Trunk Release with a scan tool. The Rear Compartment Lid Release Actuator should release the trunk lid.
- If the trunk latch does not does not release, refer to Rear Compartment Lid Malfunction.

CIRCUIT/SYSTEM TESTING

Rear Compartment Lid Release Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the Rear Compartment Lid Release Switch.
2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit terminal A 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 is Inactive.
- If not the specified value, test the signal circuit terminal C 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 C and ground. Verify the scan tool Trunk Release 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 Rear Compartment Lid Release Switch.

Rear Compartment Lid Release Malfunction
1. Ignition OFF, disconnect the harness connector at the Underhood Fuse Block.
2. Connect a test lamp between the control circuit terminal B10 and B+.
3. 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 ground. If the circuit tests normal, replace the BCM.
- 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 BCM.
4. Ignition OFF, connect the harness connector at the Underhood Fuse Block. Disconnect the harness connector at the Rear Compartment Lid Release Actuator.
5. Test for less than 1 ohm of resistance between the Rear Compartment Lid Release Actuator ground circuit terminal 3 and ground
- If greater than the specified range, test the ground circuit for an open/high resistance.
6. Connect a test lamp between the control circuit terminal 4 and ground.
7. 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 Underhood Fuse Block.
- If the test lamp is always OFF and the circuit fuse is good, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the Underhood Fuse Block.
- If the test lamp is always OFF and the circuit fuse is open, test the control circuit for a short to ground. If the circuit tests normal, test or replace the Rear Compartment Lid Release Actuator.
8. If all circuits test normal, test or replace the Rear Compartment Lid Release Actuator.

COMPONENT TESTING

Rear Compartment Lid Release Actuator
1. Ignition OFF, disconnect the harness connector at the Rear Compartment Lid Release Actuator.
2. Install a 20-amp fused jumper wire between the control circuit terminal 4 and 12 volts. Install a jumper wire between the ground circuit terminal 3 and ground. Verify the rear compartment lid release actuator activates.
- If the actuator does not perform as specified, replace the rear compartment lid release actuator.

Rear Compartment Lid Release Switch
1. Ignition OFF, disconnect the harness connector C at the Rear Compartment Lid Release Switch.
2. Test for infinite resistance between the signal terminal C and the ground circuit terminal A with the switch in the open position.
- If not the specified value, replace the Rear Compartment Lid Release Switch.
3. Test for less than 2 ohms between the signal terminal C and the ground circuit terminal A with the switch in the closed position.
- If greater than the specified range, replace the Rear Compartment Lid Release Switch

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
- Underhood Electrical Center or Junction Block Bracket Replacement
- Rear Compartment Lid Latch Replacement
- Control Module References for BCM replacement, setup, and programming Programming and Relearning
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