Liftgate Release Malfunction Manual Liftgate

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

Before testing can be performed the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power for the appropriate procedure.

Schematic Reference

Release Systems Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Liftgate Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON observe the scan tool Liftgate Handle Sw. parameter while using the liftgate handle switch, the parameter should change from Inactive to Active.

⇒	If the value does not change, refer to Liftgate Handle Switch Malfunction.

2. Command the liftgate to release by using the liftgate handle switch, the liftgate latch assembly should release the liftgate.

⇒	If the liftgate latch assembly does not release the liftgate, refer to Liftgate Latch Malfunction.

Liftgate Handle Switch Malfunction

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

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

3. Ignition ON, verify the scan tool Liftgate Handle Sw. parameter is Inactive.

⇒	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. Connect a 3A fused jumper wire between the signal circuit terminal A and the ground circuit terminal B. Verify the scan tool Liftgate Handle Sw. parameter is Active.

⇒	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 handle switch.

Liftgate Latch Malfunction

1. Ignition OFF, disconnect the harness connector at the liftgate latch assembly.
2. 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.

3. Connect the harness connector at the liftgate latch assembly.
4. Momentarily connect a 15A fused jumper wire between the L/GATE RELSE fuse test point and B+, verify the liftgate latch assembly activates.

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

⇒	If the liftgate latch assembly does not activate and the jumper wire fuse opens, test the control circuit for a short to ground. If the circuit tests normal, replace the liftgate latch assembly.

5. Disconnect the X7 harness connector at the BCM.
6. Test for infinite resistance between the control circuit terminal listed below and ground:

•	Control circuit terminal 1

•	Control circuit terminal 3

⇒	If less than the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the underhood fuse block

7. Connect a 3A fused jumper wire between the control circuit terminal 3 and B+, momentarily connect a jumper wire between the control circuit terminal 1 and ground. Verify the liftgate latch assembly activates.

⇒	If the liftgate latch does not activate, test either control circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the underhood fuse block.

8. If all circuits test normal, replace the BCM

Liftgate Latch

1. Ignition OFF, disconnect the harness connector at the liftgate latch assembly.
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 assembly activates.

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

Liftgate Release Switch

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

⇒	If not the specified value, replace the liftgate handle switch.

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

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.