For 1990-2009 cars

### 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
--- | --- | --- | --- | ---
Liftgate Relay Switch B+ | 2 | 2 | -- | --
Liftgate Release Switch Signal | B3265 00 | B3265 00 | B3265 00 | --
Liftgate Relay Low Control | -- | 2 | 2 | --
Liftgate Relay Coil High Control | B2495 02 | 2 | B2495 01 | --
Liftgate Latch Control | 2 | 2 | 2 | --
Liftgate Release Switch Ground | -- | 1 | 1 | --
Liftgate Latch Ground | -- | 2 | 2 | --
1. Liftgate Release Switch Inoperative 2. Liftgate Latch Inoperative

### Circuit/System Description

The liftgate switch is an input to the body control module (BCM). The BCM supplies battery voltage to the signal circuit and when the liftgate switch is activated the signal circuit voltage goes low. The BCM controls the liftgate release actuator assembly through the LIFTGATE relay. When the liftgate switch signal is activated, the BCM enables the LIFTGATE relay by applying battery voltage to the liftgate relay circuit and the relay is energized when the BCM grounds the LIFTGATE relay control circuit. When the relay is energized battery voltage is supplied to the liftgate release actuator assembly through the liftgate release actuator control circuit.

### Reference Information

#### Schematic Reference

Release Systems Schematics

#### Connector End View Reference

Component 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

Control Module References for scan tool information

### Circuit/System Verification

1. Ignition ON, observe the scan tool Trunk Release Solenoid Command parameter while pressing and releasing the liftgate release switch. The parameter should change between On and Off.

⇒ | If the parameter does not change, refer to Liftgate Release Switch Malfunction.

2. Command the liftgate release by pressing the liftgate release switch. The liftgate latch should release the liftgate.

⇒ | If the liftgate latch does not release the liftgate, refer to Liftgate Release Malfunction.

### Circuit/System Testing

#### Liftgate Release Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the liftgate release switch.
2. Test for less than 1 ohm between the ground circuit terminal C and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, test for greater than 9 volts between the signal circuit terminal A and ground.

⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Trunk Release Solenoid parameter is On.

⇒ | If not the specified value, test the signal circuit for a short to voltage. 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 X2 harness connector at the I/P fuse block.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for short to ground or an open/high resistance.

3. Ignition OFF, connect the X2 harness connector and disconnect the X3 harness connector at the I/P fuse block.
4. Verify that a test lamp does not illuminate between the control circuit terminal 22 and ground.

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage.

5. Disconnect the harness connector at the liftgate latch.
6. Test for less than 1 ohm between the ground circuit terminal 3 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

7. Connect the harness connector at the liftgate latch.
8. Ignition ON, connect a 15A fused jumper wire between the control circuit terminal 22 and B+. Verify the liftgate latch activates.

⇒ | If the liftgate latch does not activate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the liftgate latch.

9. Connect a test lamp between the circuit terminal 20 and ground.
10. Command the liftgate latch ON and OFF by pressing and releasing the liftgate release switch. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

11. Connect a test lamp between the control circuit terminal 9 and B+.
12. Command the liftgate latch ON and OFF by pressing and releasing the liftgate release switch. The test lamp should turn ON and OFF while changing between the commanded states.

⇒ | 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.

13. If all circuits test normal, replace the I/P fuse block.

### Component Testing

#### Liftgate Latch

1. Ignition OFF, disconnect the harness connector at the liftgate latch.
2. Install a 15A fused jumper wire between the control terminal 1 and 12 volts. Install a jumper wire between the ground terminal 3 and ground. Verify the liftgate latch activates.

⇒ | If the liftgate latch does not perform as specified, replace the liftgate latch.

#### Liftgate Release Switch

1. Ignition OFF, disconnect the harness connector at the liftgate release switch.
2. Test for infinite resistance between the signal terminal A and the ground terminal C with the switch in the open position.

⇒ | If not the specified value, replace the liftgate release switch.

3. Test for less than 2 ohms between the signal terminal A and the ground terminal C with the switch in the closed position.

⇒ | If greater than the specified range, replace the liftgate release switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Liftgate Outside Handle Replacement

• | Instrument Panel Electrical Center or Junction Block Replacement

• | Control Module References for BCM replacement, setup, and programming