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B396A




Liftgate Motor Power Open/Close Malfunction - DTC B396A

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.

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 liftgate motor is a bi-directional motor and open or close operation is the result of the direction of the motor rotation. The liftgate control module controls the liftgate motor through the control circuits by supplying power and ground in the appropriate polarity. The motor control circuits are monitored by the liftgate control module prior to activation for a high or low condition and during motor operation for any irregular current flow conditions.

Conditions for Running the DTC

* The system voltage is 9-16 V.

* Power open or close function is initiated.

Conditions for Setting the DTC

B396A 01

The liftgate control module detects a short to voltage in a liftgate motor control circuit.

B396A 02

The liftgate control module detects a short to ground in a liftgate motor control circuit.

B396A 04

The liftgate control module detects an open/high resistance in a liftgate motor control circuit or the liftgate control module B+ circuit. A short to ground in the liftgate control module B+ circuit.

Action Taken When the DTC Sets

The power liftgate may be inoperative in the power mode and in the manual mode.

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.

* When the fault is no longer present, the DTC will be a history DTC.

* A history DTC will clear after 50 ignition cycles.

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.

* DTC B396A 01 may set as current or history when the liftgate control module detects erratic voltage levels in the electrical system and does not affect the operation of the power liftgate. If this DTC is set and the liftgate functions normally, clear the DTC

Reference Information

Schematic Reference

Liftgate Schematics Liftgate Schematics

Connector End View Reference

Component Connector End Views Sunshade - Left Front

Description and Operation

Liftgate Description and Operation Liftgate

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 Programming and Relearning for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Select the S45B liftgate control switch-interior to the 3/4 or Max position

3. Verify the function of the liftgate while commanding the OPEN and CLOSE with the S45B liftgate control switch-interior.

• If the power open and power close does not work
Refer to Circuit/System Testing

• If the power open and power close works

4. All OK.

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the X1 harness connector at the K39 liftgate control module, ignition ON.

2. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground.

• If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF.

2. Test for less than 2 ohms in the B+ circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.

• If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF.

2. Test for infinite resistance between the B+ circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance

3. Disconnect the harness connector at the A23C liftgate latch assembly and the M17 liftgate motor assembly.

4. Test for infinite resistance between each control circuit listed below and ground.

* Control circuit terminal 1 X1 - A23C liftgate latch assembly

* Control circuit terminal 2 X1 - A23C liftgate latch assembly

* Control circuit terminal 1 X3 - M17 liftgate motor assembly

* Control circuit terminal 2 X3 - M17 liftgate motor assembly

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the A23C liftgate latch assembly or the M17 liftgate motor assembly.

• If the test lamp illuminates

3. Ignition OFF, connect the X1 harness connector at the K39 liftgate control module. Disconnect the harness connector at the M17 liftgate motor assembly.

4. Test for less than 30k ohms between the control circuit terminal A and ground.

• If 30k ohms or greater

1. Ignition OFF, disconnect the harness connector at the K39 liftgate control module.

2. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K39 liftgate control module.

• If less than 30k ohms

5. Test for less than 30k ohms between the control circuit terminal B and ground.

• If 30k ohms or greater

1. Ignition OFF, disconnect the harness connector at the K39 liftgate control module.

2. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K39 liftgate control module.

• If less than 30k ohms

6. Connect a test lamp between control circuit terminal A and control circuit terminal B, ignition ON.

7. Verify the test lamp turns ON when commanding the OPEN state by pressing the S46 liftgate handle switch

• If the test lamp remains OFF during the OPEN command

1. Ignition OFF, disconnect the harness connector at the K39 liftgate control module.

2. Test for infinite resistance between each control circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the K39 liftgate control module.

• If the test lamp turns ON during the OPEN command

8. Verify the test lamp turns ON when commanding the CLOSE state by pressing the B70 liftgate close switch

• If the test lamp remains OFF during the CLOSE command

1. Ignition OFF, disconnect the harness connector at the K39 liftgate control module.

2. Test for infinite resistance between each control circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the K39 liftgate control module.

• If the test lamp turns ON during the CLOSE command

9. Test or replace the M17 liftgate motor assembly.

Repair Instructions

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

* Liftgate Hydraulic Pump Replacement Liftgate Hydraulic Pump Replacement

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

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