GM Service Manual Online
For 1990-2009 cars only

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 Key Switch Signal

3

3

3

--

Trunk Release Control Signal

5

5

B3265

--

Trunk Release Switch Signal - Exterior

B3618

2

2

--

Rear Compartment Lid Pull Down Actuator Signal

B1297

B1297

B1297

--

Rear Compartment Lid Pull Down Actuator B+

5

5

5

--

Rear Compartment Lid Release Close Switch B+

4

4

B3641

--

Trunk Release Switch Supply Voltage

1

1

1

--

Rear Compartment Lid Pull Down Actuator Ground

5

5

5

--

Rear Compartment Lid Release Switch Exterior Ground

2

2

2

--

Rear Compartment Lid Release Switch Interior Ground

1

1

1

--

Rear Compartment Lid Release Close Switch Ground

4

4

4

--

  1. Trunk Release Inoperative from Interior Switch
  2. Trunk Release Inoperative from Exterior Switch
  3. Trunk Release Inoperative from Key Switch
  4. Trunk Release Inoperative from Lid Close Switch
  5. Trunk Release Inoperative from All Switches

Circuit/System Description

The folding top module controls the opening and closing of the rear compartment lid based on an input from either the interior lid release switch, exterior lid release switch, or the lid close switch.

The interior rear compartment lid release switch is located in the passenger compartment, near the driver left knee bolster. This switches function is to open the rear compartment lid. With the switch pressed, the trunk release switch supply voltage circuit from the body control module (BCM) is grounded. Upon seeing this input, the BCM will request the folding top module begin raising or lowering the rear compartment lid.

The exterior rear compartment lid release switch is located at the rear of the vehicle, under the upper lip of the license plate pocket. This switches function is only to open the rear compartment lid. With the switch pressed, the trunk release switch signal circuit from the remote control door lock receiver (RCDLR) is grounded. Upon seeing this input, the RCDLR will request the folding top module begin raising or lowering the rear compartment lid.

The rear compartment lid close switch is located on the underside of the rear compartment lid; it is only accessible when the lid is open. This switches function is only to close the lid. With the switch pressed, voltage supplied from the AC LATCH PK BRK B fuse is applied to the rear compartment lid release close switch signal circuit at the folding top module. Upon seeing this input, the folding top module will begin raising or lowering the rear compartment lid.

Diagnostic Aids

If the front tonneau is not in its fully closed position, the rear compartment lid will not release. A driver information center (DIC) message will not be displayed to notify the driver should this occur. Air turbulence with the vehicle top lowered or jarring of the vehicle while driving may cause the front tonneau to lift, thus creating an inoperative rear compartment lid. In this instance, the front tonneau must be resecured prior to attempting a lid release function.

The rear compartment lid release will be inoperative if the vehicle is placed in valet mode. This is by design and does not designate a malfunction. Lid release functions will resume once the vehicle is taken out of valet mode.

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 Testing

Trunk Release Inoperative from Interior Switch

  1. Ignition OFF, disconnect the harness connector at the interior rear compartment lid release switch.
  2. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal A.
  3. If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool tunk release switch parameter is INACTIVE.
  5. If not the specified value, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool trunk release switch parameter is ACTIVE.
  7. 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.
  8. If all circuits test normal, test or replace the interior rear compartment lid release switch.

Trunk Release Inoperative from Exterior Switch

  1. Ignition OFF, disconnect the harness connector at the exterior rear compartment lid release switch.
  2. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms between the ground circuit terminal C and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool ext. rear compartment lid release sw. parameter is INACTIVE.
  5. If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the remote control door lock receiver (RCDLR).
  6. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool ext. rear compartment lid release sw. parameter is ACTIVE.
  7. 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 remote control door lock receiver (RCDLR).
  8. If all circuits test normal, test or replace the exterior rear compartment lid release switch.

Trunk Release Inoperative from Key Switch

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid pull down actuator.
  2. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms between the ground circuit terminal F and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool trunk key cylinder switch parameter in Theft Data is INACTIVE.
  5. If not the specified value, test the signal circuit terminal E for a short to ground. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool trunk key cylinder switch parameter is ACTIVE.
  7. 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.
  8. If all circuits test normal, test or replace the rear compartment lid pull down actuator.

Trunk Release Inoperative from Lid Close Switch

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid/release close switch.
  2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal D and ground.
  3. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Verify the scan tool rear compartment lid pull down switch is INACTIVE.
  5. If not the specified value, test the signal circuit terminal A for a short to voltage. If the circuit tests normal, replace the folding top control module.
  6. Install a 3A fused jumper wire between the signal circuit terminal A and the B+ circuit terminal D. Verify the scan tool rear compartment lid pull down switch is ACTIVE.
  7. If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the folding top control module.
  8. If all circuits test normal, test or replace the rear compartment lid/release close switch.

Trunk Release Inoperative from All Switches

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid pull down actuator.
  2. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms between the ground circuit terminal F and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal H and ground.
  5. 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 or replace the rear compartment lid pull down actuator.
  6. Connect a test lamp between the control circuit terminal B and the B+ circuit terminal H.
  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.
  8. 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.
  9. If all circuits test normal, test or replace the rear compartment lid pull down actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Compartment Lid Latch Replacement
    •  Rear Compartment Lid Pulldown Switch Replacement
    •  Control Module References for BCM, RCDLR , or folding top control module replacement, setup and programming