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 (Procedures) 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 (Connector End Views By Name)
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. Using either the power door lock switches or the remote keyless transmitter, LOCK all doors then UNLOCK all doors. This will set the liftgate module door lock status to unlock.
2. With the liftgate closed, select either the 3/4 or Max position on the S45B liftgate control switch-interior and activate the power open. The liftgate should power open
3. With the liftgate open, activate the power close. The liftgate should power close
Circuit/System Testing
1. Ignition OFF, disconnect the X2 harness connector at the K39 liftgate control module.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ fuse is open, test each of the circuits listed below for a short to ground or a faulty motor.
* 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
* Control circuit terminal 2 X3 - M17 liftgate motor
3. Ignition OFF, connect the X2 harness connector at the K39 liftgate control module and disconnect the harness connector at the M17 liftgate motor assembly.
4. Test for less than 30k ohm between the control circuit terminal A and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K39 liftgate control module.
5. Test for less than 30k ohm between the control circuit terminal B and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K39 liftgate control module.
Note: Verify that the interior liftgate control switch is in the 3/4 or MAX position
6. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
7. Ignition ON, with the liftgate in the open position, command the liftgate to CLOSE by pressing the B70 liftgate close switch. The test lamp should illuminate during the CLOSE command.
• If the test lamp does not illuminate, test control circuit terminal A for a short to ground. If the circuit tests normal, replace the K39 liftgate control module.
8. With the liftgate in the closed position, command the liftgate to OPEN by pressing the S46 liftgate handle switch. The test lamp should illuminate during the OPEN command.
• If the test lamp does not illuminate, test control circuit terminal B for a short to ground. If the circuit tests normal, replace the K39 liftgate control module.
9. If all circuits test normal, 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