B396A

DTC B396A

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors
DTC B396A 01
- Liftgate Motor Control Circuit Short to Battery

DTC B396A 02
- Liftgate Motor Control Circuit Short to Ground

DTC B396A 04
- Liftgate Motor Control Circuit Open

Diagnostic Fault Information






Circuit/System Description

The power liftgate motor is a bi-directional motor that is controlled by the liftgate control module (LGM). The LGM controls the liftgate motor through the control circuits by suppling power and ground in the appropriate polarity. The direction the motor operates is determined by which of the control circuits is supplied power and which is grounded. The LGM varies the current flow through the motor ground circuit to control the speed of the motor as necessary. For more detailed information concerning power liftgate operation refer to Liftgate Description and Operation.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

* DTC B396A 01 will set when the LGM detects a short to voltage in the liftgate motor open control circuit or the liftgate motor close control circuit.
* DTC B396A 02 will set when the LGM detects a short to ground in the liftgate motor open control circuit or the liftgate motor close control circuit.
* DTC B396A 04 will set when the LGM detects an open/high resistance in the liftgate motor open control circuit or the liftgate motor close control circuit.

Actions Taken When the DTC Sets

* If the liftgate is in motion when the DTC sets, liftgate operation will be disabled and resort to manual operation.
* If the liftgate is not in motion when the DTC sets, all liftgate functions will be disabled.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* You issue a scan tool CLEAR DTCs command.

Diagnostic Aids

* In some cases, the LGM may interpret circuit faults as if the liftgate has encountered an object in its travel and reverse direction.
* Whenever the LGM is disconnected or loses power, the ignition must be cycled OFF then ON.

Circuit/System Testing

1. Ignition OFF, disconnect the C3 harness connectors at the LGM.
2. Ignition OFF, test for less than 1 ohm of resistance between the control circuit terminal 1 and control circuit terminal 2.

• If greater than the specified range, replace the liftgate motor assembly.

3. Ignition OFF, verify that continuity is not present between both motor control circuit terminals at the C3 harness connector and ground.

• If continuity is present, replace the liftgate motor assembly.

4. If all circuits test normal, replace the LGM.

Repair Instructions

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

* Power Liftgate Motor Replacement
* Control Module References for LGM replacement, setup, and programming. Programming and Relearning