B396D

Liftgate Interior Release Open/Close Switch Malfunction - DTC B396C or B396D

Diagnostic Instructions

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

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information






Circuit/System Description

The interior liftgate control switch has of a push button switch to command the liftgate to open and close. The liftgate module monitors the voltage level on the open/close signal circuit, when the switch is not being pressed the voltage level is at the system voltage. When the switch is pressed a contact within the interior liftgate control switch closes providing a ground path for the signal circuit causing the voltage level to drop to near zero volts. The liftgate module will detect the voltage drop and will then command the liftgate to open or close depending upon the current state of the liftgate at the time the switch is pressed.

Diagnostic Aids

* If the liftgate will not release from the closed position, refer to Opening the Liftgate Without Electrical Power Service and Repair for the appropriate procedure

* Whenever the liftgate control module loses power or is disconnected, the ignition must be cycled OFF then ON in order to reactivate the liftgate control module.

Reference Information

Schematic Reference

Liftgate Schematics Liftgate Schematics

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

Description and Operation

Rear Hatch/Gate Description and Operation Rear Hatch/Gate

Electrical Information Reference

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Circuit Testing Circuit Testing

* Wiring Repairs Wiring Repairs

* Connector Repairs Connector Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Observe the scan tool LGM Disable Switch parameter while pressing and depressing the Liftgate Enable/Disable button on the interior liftgate control switch. The parameter should change from Inactive to Active.

2. Observe the scan tool LGM Front Control Switch parameter while pressing and releasing the liftgate button on the interior liftgate control switch. The parameter should change from Inactive and Active.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the I/P multifunction switch.

2. Test for less than 10 ohms between the ground circuit terminal 3 and ground.

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

3. Ignition ON, verify the scan tool LGM Disable Switch parameter is Inactive.

• If not the specified value, test the signal circuit terminal 8 for a short to ground. If the circuit tests normal, replace the liftgate control module.

4. Install a 3 A fused jumper wire between the signal circuit terminal 8 and ground. Verify the scan tool LGM Disable Switch 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 liftgate control module.

5. Verify the scan tool LGM Front Control Switch parameter is Inactive.

• If not the specified value, test the signal circuit terminal 7 for a short to ground. If the circuit tests normal, replace the liftgate control module.

6. Install a 3 A fused jumper wire between the signal circuit terminal 7 and ground. Verify the scan tool LGM Front Control Switch 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 liftgate control module.

7. If all circuits test normal, test or replace the I/P multifunction switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the I/P multifunction switch.

2. Test for infinite resistance between the signal terminal 7 and the ground terminal 3 with the liftgate open switch in the inactive position.

• If not the specified value, replace the I/P multifunction switch.

3. Test for less than 3 ohms between the signal terminal 7 and the ground terminal 3 with the liftgate open switch in the active position.

• If greater than the specified range, replace the I/P multifunction switch.

4. Test for infinite resistance between the signal terminal 8 and the ground terminal 3 with the liftgate disable switch in the inactive position.

• If not the specified value, replace the I/P multifunction switch.

5. Test for less than 3 ohms between the signal terminal 8 and the ground terminal 3 with the switch in the disable position

• If greater than the specified range, replace the I/P multifunction switch.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Accessory Switch Replacement Service and Repair

* Control Module References Control Module References for the liftgate control module replacement, programming and setup