GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2006 🢒 Rendezvous - FWD 🢒 Body 🢒 Body Rear End 🢒 Hatch Release Inoperative

Diagnostic Fault Information

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

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Liftgate Lock Motor Unlock Control Circuit

1

1

1

--

Liftgate Lock Motor Lock Control Circuit

1

1

1

--

Liftgate Release Switch Signal

1, 2

1, 2

1, 2

--

Liftgate Release Switch Ground

--

1, 2

1, 2

--

1. Liftgate Release Malfunction

2. Liftgate Release Switch Malfunction

Circuit/System Description

The liftgate can be unlocked by operating the liftgate release switch on the instrument panel. Battery voltage is supplied to the liftgate actuator through the body control module (BCM). The BCM will pulse the liftgate actuator when an unlock input is received through the key fob, or the instrument panel switch.

Reference Information

Schematic Reference

Body Rear End Schematics

Connector End View Reference

Body Rear End Connector End Views

Description and Operation

Rear Hatch/Gate Description and Operation

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Verification
  1. Ignition ON, observe the Liftgate Release switch parameter while pressing the Liftgate Release Switch. The reading should change between Lock and Unlock.
    2. ⇒If the reading does not change between commanded states, refer to Liftgate Release Switch Malfunction.
  2. Ignition ON, command the Liftgate Latch Assembly to Lock and Unlock with a scan tool, the liftgate should Lock and Unlock.
    3. ⇒If the liftgate does not Lock and Unlock when changing between commanded states, refer to Liftgate Release Malfunction.

Circuit/System Testing

Liftgate Release Switch Malfunction

  1. Ignition OFF, disconnect the harness connector C1 at the Liftgate Release switch.
  2. Ignition OFF, test for less than 1.0 ohm for resistance between the ground circuit terminal C and ground.
    3. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool Liftgate Release is Inactive.
    4. ⇒If not the specified value, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the BCM.
  4. Install a 3-amp fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool Liftgate Release is Active.
    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.
  5. If all circuits test normal, test or replace the Liftgate Release switch.

Liftgate Release Malfunction

  1. Ignition OFF, disconnect the harness connector at the Liftgate Latch Assembly.
  2. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal B and ground.
    3. ⇒If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.
  3. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal A and ground.
    4. ⇒If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.
  4. Connect a test lamp between control circuit terminal B and control circuit terminal A.
  5. Command the Liftgate Latch Assembly to LOCK/UNLOCK with a scan tool. The test lamp should turn ON when commanding the LOCK and UNLOCK states.
    6. ⇒If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuits. If the circuits test normal, replace the BCM.
  6. If all circuits test normal, test or replace the Liftgate Latch Assembly.

Component Testing

Liftgate Release Switch

  1. Ignition OFF, disconnect the harness connector at the Liftgate Release switch.
  2. Test for infinite resistance between the signal terminal D and the ground circuit terminal C with the switch in the open position.
    3. ⇒If not the specified value, replace the Liftgate Release switch.
  3. Test for less than 2.0 ohms between the signal terminal D and the ground circuit terminal C with the switch in the closed position.
    4. ⇒If greater than the specified range, replace the Liftgate Release switch.

Liftgate Latch Assembly

  1. Install a 20-amp fused jumper wire between the control terminal B and 12 volts. Momentarily install a jumper wire between the control terminal A and ground. The Liftgate Latch Assembly should perform the LOCK/ UNLOCK function.
    2. ⇒If the function does not perform as specified, replace the Liftgate Latch Assembly.
  2. Reverse the jumper wires, the Liftgate Latch Assembly should perform the LOCK/UNLOCK function.
    3. ⇒If the function does not perform as specified, replace the Liftgate Latch Assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Liftgate Latch Replacement
    •  Instrument Panel Multifunction Switch Assembly Replacement
    •  Control Module References for BCM replacement, setup and programming.