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

Ajar Indicator Signal

2

1

1

--

Ajar Switch Signal

2

1

1

--

Ajar Switch Ground

--

1

--

--

1. Ajar Indicator is Inoperative

2. Ajar Indicator is always On

Circuit/System Description

The latch ajar switches provide a single input to the midgate control module. The switch signal circuit is supplied accessory voltage through a resistor and monitored by the midgate control module. When the midgate is opened both of the latch ajar switches close and the circuit is pulled low. The midgate control module provides an ajar signal to the body control module through the midgate ajar indicator signal circuit. The body control module supplies the signal circuit with accessory voltage through a resistor and monitors the voltage level. When the midgate is ajar the midgate control module will ground the ajar indicator signal circuit and the voltage monitored by the body control module will drop indicating the circuit is active.

Reference Information

Schematic Reference

Interior Lights Schematics

Connector End View Reference

Vehicle Access Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Testing

Ajar Indicator is always On

  1. Disconnect the midgate control module connector.
  2. Ignition ON, verify that the REAR ACCESS OPEN message is not displayed.
  3. If the message is displayed test the midgate ajar indicator signal circuit for a short to ground. If the circuit tests normal replace the body control module.
  4. Connect the midgate control module connector.
  5. Disconnect the right side midgate latch.
  6. Ignition ON, verify that the REAR ACCESS OPEN message is not displayed.
  7. If the message is displayed test the midgate ajar switch signal circuit for a short to ground.
  8. If all the circuits test normal replace the midgate control module.

Ajar Indicator is Inoperative

  1. Disconnect the midgate control module connector.
  2. Connect a fused jumper wire form the midgate ajar indicator signal circuit to ground.
  3. Ignition ON, verify that the REAR ACCESS OPEN message is displayed.
  4. If the message is not displayed test the midgate ajar indicator signal circuit for an open/high resistance or short to voltage. If the circuit tests normal replace the body control module.
  5. Disconnect the left side midgate latch.
  6. Connect a test lamp from battery voltage to the midgate ajar switch ground circuit.
  7. If the test lamp does not illuminate repair the ground circuit for an open/high resistance.
  8. Connect the left side midgate latch.
  9. Disconnect the right side midgate latch.
  10. With the midgate open connect a test lamp from battery voltage to the midgate ajar switch signal circuit 6252.
  11. If the test lamp does not illuminate test the midgate ajar switch signal circuit 6252 for an open/high resistance. If the circuit tests normal replace the left side midgate latch.
  12. Connect the right side midgate latch.
  13. With the midgate open connect a test lamp from battery voltage to the midgate ajar switch signal circuit 5459 in the control module connector.
  14. If the test lamp does not illuminate test the midgate ajar switch signal circuit 5459 for an open/high resistance. If the circuit tests normal replace the right side midgate latch.
  15. If all the circuits test normal replace the midgate control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Midgate Latch Replacement
    •  Control Module References for body control module or midgate motor module replacement, programming, and setup.