For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Trunk Relay B+ | 1 | 1 | -- | --
Rear Compartment Lid Release Actuator Control | 1 | 1 | 1 | --
Trunk Release Relay Control | B3265 02 | 1 | -- | --
Rear Compartment Lid Release Actuator Ground | -- | 1 | 1 | --
Trunk Relay Ground | -- | 1 | 1 | --
1. Trunk Release Malfunction

### Circuit/System Description

The exterior rear compartment lid release switch receives a signal from the body control module (BCM). When the exterior rear compartment lid release switch is activated the signal circuit is pulled to ground. The BCM applies battery positive voltage to the trunk release relay control circuit which energizes the relay. The trunk release relay is grounded 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Luggage Compartment Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References 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 trunk 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.

### Circuit/System Testing

#### Rear Compartment Lid Release Malfunction

1. Ignition OFF, disconnect the KR95B Rear Compartment Lid Release Relay.
2. Test for less than 5 Ω between the ground circuit terminal 86 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 B+ circuit terminal 30 and ground.

⇒ | If the test lamp illuminates, test the B+ circuit for a short to voltage.

4. Verify that a test lamp illuminates between the control circuit terminal 85 and ground.

⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance.

5. Ignition OFF, disconnect the harness connector at the M41 Rear Compartment Lid Latch Release Actuator.
6. Test for less than 1 Ω between the ground circuit terminal 2 and ground.

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

7. Connect the harness connector at the M41 Rear Compartment Lid Latch Release Actuator.
8. Ignition ON, connect a 15 A 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 M41 Rear Compartment Lid Latch Release Actuator

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 K9 Body Control Module (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 K9 Body Control Module (BCM).

11. If all circuits test normal, test or replace the KR95B Rear Compartment Lid Release Relay.

#### Exterior Trunk Release Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the S58A Rear Compartment Lid Release Switch - Exterior.
2. Test for less than 1 Ω between the ground circuit terminal 3 and ground.

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

3. Connect the harness connector at the S58A Rear Compartment Lid Release Switch - Exterior and disconnect the X6 harness connector at the K9 Body Control Module (BCM).
4. Connect a test lamp between the signal circuit terminal 15 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 continuously illuminates, test the signal circuit for a short to ground or and open/high resistance. If the circuit tests normal, replace the S58A Rear Compartment Lid Release Switch - Exterior.

⇒ | If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the S58A Rear Compartment Lid Release Switch - Exterior.

6. If all circuits test normal, replace the K9 Body Control Module (BCM).

### Component Testing

#### Rear Compartment Lid Latch

1. Ignition OFF, disconnect the harness connector at the M41 Rear Compartment Lid Latch Release Actuator.
2. Install a 15A fused jumper wire between the control terminal 1 and 12 V. Install a jumper wire between the ground terminal 2 and ground. Verify the M41 Rear Compartment Lid Latch Release Actuator activates.

⇒ | If the actuator does not perform as specified, replace the M41 Rear Compartment Lid Latch Release Actuator.

#### Rear Compartment Lid Release Switch

1. Ignition OFF, disconnect the harness connector at the S58A Rear Compartment Lid Release Switch - Exterior.
2. Test for infinite resistance between the signal terminal 1 and the ground terminal 3 with the switch in the open position.

⇒ | If not the specified value, replace the S58A Rear Compartment Lid Release Switch - Exterior.

3. Test for less than 2 Ω between the signal terminal 1 and the ground terminal 3 with the switch in the closed position.

⇒ | If greater than the specified range, replace the S58A Rear Compartment Lid Release Switch - Exterior.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Rear Compartment Lid Release Switch Replacement

• | Rear Compartment Lid Latch Replacement

• | Relay Replacement

• | Control Module References for BCM replacement, setup, and programming