B396A
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 volts.
* Power open or close function is initiated.
Conditions for Setting the DTC
B396A 01
The liftgate module detects a short to voltage in a liftgate motor control circuit.
B396A 02
The liftgate module detects a short to ground in a liftgate motor control circuit.
B396A 04
The liftgate module detects an open/high resistance in a liftgate motor control circuit.
Action Taken When the DTC Sets
The power liftgate will only function 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
Note: Before testing can be performed, the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power (Procedures) for the appropriate procedure.
Note: DTC B396A 01 may set as current or history when the liftgate 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.
Whenever the liftgate module loses power or is disconnected, the ignition must be cycled OFF then ON in order to reactivate the liftgate module.
Reference Information
Schematic Reference
Liftgate Schematics (Liftgate Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Liftgate Description and Operation (Liftgate Description and Operation)
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
Ignition ON, doors UNLOCKED, observe the function of the liftgate while pressing the S46 liftgate handle switch, the liftgate latch should release the liftgate and the liftgate should power OPEN.
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the K39 liftgate 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
3. Ignition OFF, connect the X1 harness connector at the K39 liftgate module and 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 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 module.
5. Test for less than 30k ohms 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 module.
Note: Verify that the interior liftgate control switch is in the Garage Mode or the Full Open Mode
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 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 module.
9. If all circuits test normal, test or replace the M17 liftgate motor assembly.
Component Testing
Liftgate Motor
1. Ignition OFF, disconnect the harness connector at the M17 liftgate motor assembly.
2. Install a 30 A fused jumper wire between one of the control terminals and 12 V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the M17 liftgate motor assembly should perform the OPEN and CLOSE functions.
• If it does not perform as specified, replace the M17 liftgate motor assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair..
* Liftgate Hydraulic Pump Replacement (Liftgate Hydraulic Pump Replacement)
* Control Module References (Programming and Relearning) for liftgate module replacement, setup and programming