Trunk Release Malfunction
Trunk Release Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The rear compartment lid can be released by operating the rear compartment lid release switch or by pressing the rear compartment lid release button on the remote keyless entry transmitter. The gear selector must be in Park for the trunk to release.
The body control module (BCM) monitors the signal circuit to the rear compartment lid release switch. When the rear compartment lid release switch is pressed, the trunk release signal is pulled low within the BCM. In response, the BCM applies ground to the trunk 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 control circuit to the rear compartment lid latch. The rear compartment lid latch, then releases the rear compartment lid so that it may be manually raised to an open position.
Reference Information
Schematic Reference
Release Systems Schematics Release Systems Schematics
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Luggage Compartment Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the scan tool Int. Trunk/Liftglass Sw. parameter while pressing the rear compartment lid release switch. The parameter should change between Active and Inactive.
• If the value does not change, refer to Rear Compartment Lid Release Switch Malfunction
2. Command the Trunk Release with a scan tool, the rear compartment lid latch should release the trunk lid.
• If the rear compartment lid latch does not release, refer to Rear Compartment Lid Latch Release Malfunction.
Circuit/System Testing
Rear Compartment Lid Release Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the rear compartment release switch.
2. Test for less than 10 ohms between the ground circuit terminal listed below and ground:
* Ground circuit terminal 2 - S48E multifunction switch-center console (9C3)
* Ground circuit terminal 1 - S58B rear compartment lid unlatch switch-interior (9C1)
• 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 listed below for a short to ground. If the circuit tests normal, replace the K9 body control module.
* Signal circuit terminal 5 - S48E multifunction switch-center console (9C3)
* Signal circuit terminal 3 - S58B rear compartment lid unlatch switch-interior (9C1)
4. Install a 3 A fused jumper wire between the signal circuit terminal listed below and ground. Verify the scan tool Int. Trunk/Liftglass Sw. parameter is Active.
* Signal circuit terminal 5 - S48E multifunction switch-center console (9C3)
* Signal circuit terminal 3 - S58B rear compartment lid unlatch switch-interior (9C1)
• 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 K9 body control module.
5. If all circuits test normal, test or replace the rear compartment release switch.
Rear Compartment Lid Latch Release Malfunction
1. Ignition OFF, disconnect the KR95B rear compartment lid unlatch relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 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 B+ circuit terminal 86 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 B+ circuit fuse is open, test the control circuit terminal 87 for a short to ground. If the circuit tests normal, test or replace the KR95B rear compartment lid unlatch relay.
4. Verify that a test lamp illuminates between the B+ circuit terminal 30 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 M40 rear compartment lid latch.
6. Test for less than 1 ohms between the ground circuit terminal 4 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
7. Connect the harness connector at the M40 rear compartment lid latch.
8. Ignition ON, connect a 10A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the M40 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 M40 rear compartment lid latch.
9. Connect a test lamp between the B+ circuit terminal 86 and the control circuit terminal 85.
10. Command the Trunk Release with a scan tool. The test lamp should illuminate when during the RELEASE command.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 body control module.
• 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 K9 body control module.
11. If all circuits test normal, test or replace the KR95B rear compartment lid unlatch relay.
Component Testing
Rear Compartment Lid Latch
1. Ignition OFF, disconnect the harness connector at the M40 rear compartment lid latch.
2. Install a 10 A fused jumper wire between the control terminal 3 and 12 V. Install a jumper wire between the ground terminal 4 and ground. Verify the latch activates.
• If the latch does not perform as specified, replace the M40 rear compartment lid latch.
Interior Rear Compartment Lid Unlatch Switch
1. Ignition OFF, disconnect the harness connector at the S58B rear compartment lid unlatch switch-interior.
2. Test for infinite resistance between the signal terminal 3 and the ground terminal 1 with the switch in the open position.
• If not the specified value, replace the S58B rear compartment lid unlatch switch-interior.
3. Test for less than 2 ohms of between the signal terminal 3 and the ground terminal 1 with the switch in the closed position.
• If greater than the specified range, replace the S58B rear compartment lid unlatch switch-interior.
Center Console Multifunction Switch
1. Ignition OFF, disconnect the harness connector at the S48E multifunction switch-center console.
2. Test for infinite resistance between the signal terminal 5 and the ground terminal 2 with the switch in the open position.
• If not the specified value, replace the S48E multifunction switch-center console.
3. Test for less than 2 ohms of between the signal terminal 5 and the ground terminal 2 with the switch in the closed position.
• If greater than the specified range, replace the S48E multifunction switch-center console.
Relay Test
1. Ignition OFF, disconnect the KR95B rear compartment lid unlatch relay.
2. Test for 60-180 ohms between terminals 85 and 86.
• If not within the specified range, replace the KR95B rear compartment lid unlatch relay.
3. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If less than the specified value, replace the KR95B rear compartment lid unlatch relay.
4. Install a 5 A fused jumper wire between relay terminal 85 and 12 V. 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 KR95B rear compartment lid unlatch relay.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Rear Compartment Lid Latch Replacement Rear Compartment Lid Latch Replacement
* Accessory Switch Replacement (9C3) Accessory Switch Replacement (9C3)Accessory Switch Replacement (9C1) Accessory Switch Replacement (9C1)
* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)
* Control Module References Control Module References for BCM replacement, programming and setup