When the ignition is ON, the BCM supplies a reference voltage to the rear compartment lid release switch, which is part of the headlamp switch assembly, through the trunk release switch signal circuit. When the rear compartment lid release switch is operated, the trunk release signal circuit is grounded through the headlamp switch ground circuit and the reference voltage is pulled low within the BCM. In response, the BCM applies battery positive voltage to the trunk release relay control circuit, which energizes the coil side of the trunk relay. The switch side of the trunk relay then closes, supplying battery positive voltage through the relay and the relay controlled output circuit to the rear compartment lid latch. The rear compartment lid latch, then releases the trunk lid so that it may be manually raised to an open position.

Schematic Reference

Release Systems Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Luggage Compartment Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the scan tool Int. Trunk/Liftglass Sw. parameter while pressing and releasing the trunk release switch. The parameter should change between Active and Inactive.

⇒	If the value does not change, refer to Trunk Release Switch Malfunction.

2. Command the Trunk Release with a scan tool. The rear compartment lid release actuator should release the trunk lid.

⇒	If the release actuator does not release the trunk lid, refer to Trunk Release Malfunction.

Trunk Release Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Test for less than 1 ohm between the ground circuit terminal 8 and ground.

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

3. Ignition ON, verify the scan tool Int. Trunk/Liftglass Sw. parameter is Inactive.

⇒	If not the specified value, test the signal circuit terminal 9 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 9 and ground. Verify the scan tool Int. Trunk/Liftglass Sw. 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 headlamp switch.

Trunk Release Malfunction

1. Ignition OFF, disconnect the TRUNK relay.
2. Test for less than 1 ohm between the ground circuit terminal 86 and ground.

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

5. Ignition OFF, disconnect the harness connector at the rear compartment lid release actuator.
6. Test for less than 1 ohm between the ground circuit terminal 3 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 10A fused jumper wire between the B+ circuit terminal 87 and the control circuit terminal 30. Verify the rear compartment lid release actuator is activated.

⇒	If the rear compartment lid release actuator does not activate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the rear compartment lid release actuator.

9. Connect a test lamp between the control circuit terminal 85 and the ground circuit terminal 86.
10. Command the Trunk Release with a scan tool, the test lamp should illuminate during the RELEASE command.

⇒	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 relay.

Relay Test

1. Ignition OFF, disconnect the TRUNK relay.
2. Test for 60-180 ohms between terminals 85 and 86.

⇒	If not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If not the specified value, replace the relay.

4. Install a 25A fused jumper wire between relay terminal 85 and 12V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.

⇒	If greater than the specified range, replace the relay.

Rear Compartment Lid Release Actuator

1. Ignition OFF, disconnect the harness connector at the rear compartment release actuator.
2. Install a 10A fused jumper wire between the control terminal 4 and 12V. Install a jumper wire between the ground terminal 3 and ground. Verify the rear compartment release actuator activates.

⇒	If the latch does not perform as specified, replace the rear compartment release actuator.

Trunk Release Switch

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Test for infinite resistance between the signal terminal 9 and the ground terminal 8 with the switch in the open position.

⇒	If not the specified value, replace the headlamp switch.

3. Test for less than 2 ohms between the signal terminal 9 and the ground terminal 8 with the switch in the closed position.

⇒	If greater than the specified range, replace the headlamp switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.