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For 1990-2009 cars only

Trunk Ajar Indicator Malfunction Coupe

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 Ajar Switch Signal

2

1

1

--

1. Trunk Ajar Indicator Always Off

2. Trunk Ajar Indicator Always Illuminated

Circuit/System Description

The body control module (BCM) receives a discrete input from the trunk ajar switch signal circuit. The trunk ajar switch is integral to the rear compartment lid pull down actuator. When the trunk is opened, the normally open trunk ajar switch closes. With the trunk ajar switch closed, ground is provided to the trunk ajar switch signal circuit. The BCM interprets this and sends a serial data message to the instrument panel cluster (IPC). When the trunk is open/ajar and the vehicle is in any gear other than PARK, the driver information center (DIC) will display TRUNK AJAR. If the trunk is still ajar and the vehicles speed is greater than 5 km/h (3 mph) a chime will sound.

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

Ignition ON, observe the scan tool Trunk Ajar Switch parameter and the IPC TRUNK AJAR indicator while opening and closing the trunk. The parameter should change between Trunk Closed and Trunk Ajar and the TRUNK AJAR indicator should trun ON and OFF.

If the parameter changes but the TRUNK AJAR indicator is always OFF or always ON, replace the IPC.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid pull down actuator.
  2. Ignition ON, verify the scan tool Trunk Ajar Switch parameter is Trunk Closed.
  3. If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.
  4. Install a 3-A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Trunk Ajar Switch parameter is Trunk Ajar.
  5. 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.
  6. If all circuits tests normal, 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
    •  Control Module References for BCM or IPC replacement, setup and programming

Trunk Ajar Indicator Malfunction Convertible

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 Ajar Switch Signal

2

1

1

--

Rear Compartment Lid Latch Ground

--

1

1

--

1. Trunk Ajar Indicator Always Off

2. Trunk Ajar Indicator Always Illuminated

Circuit/System Description

The body control module (BCM) receives a discrete input from the trunk ajar switch signal circuit. The trunk ajar switch is integral to the rear compartment lid pull down actuator. When the trunk is opened, the normally open trunk ajar switch closes. With the trunk ajar switch closed, ground is provided to the trunk ajar switch signal circuit. The BCM interprets this and sends a serial data message to the instrument panel cluster (IPC). When the trunk is open/ajar and the vehicle is in any gear other than PARK, the driver information center (DIC) will display TRUNK AJAR. If the trunk is still ajar and the vehicles speed is greater than 5 km/h (3 mph) a chime will sound.

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

Ignition ON, observe the scan tool Trunk Ajar Switch parameter and the IPC TRUNK AJAR indicator while opening and closing the trunk. The parameter should change between Trunk Closed and Trunk Ajar and the TRUNK AJAR indicator should turn ON and OFF.

If the parameter changes but the TRUNK AJAR indicator is always OFF or always ON, replace the IPC.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid latch.
  2. Test for less than 5 ohms between the ground circuit terminal B 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 Ajar Switch parameter displays Trunk Closed.
  5. If not the specified value, test the signal circuit terminal A 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 A and ground. Verify the scan tool Trunk Ajar Switch parameter displays Trunk Ajar.
  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 latch.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid latch.
  2. Test for infinite resistance between the signal terminal A and the ground terminal B with the switch in the open position.
  3. If not the specified value, replace the rear compartment lid latch.
  4. Test for less than 2 ohms between the signal terminal A and the ground terminal B with the switch in the closed position.
  5. If greater than the specified range, replace the rear compartment lid latch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Compartment Lid Latch Replacement
    •  Control Module References for BCM or IPC replacement, setup and programming