B396C
DTC B396C
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 Descriptor
DTC B396C 08
- Liftgate Mode Switch Circuit Performance Signal Invalid
Diagnostic Fault Information
Circuit/System Description
The interior liftgate control switch contains 3 resistors which are in series for the liftgate mode, depending upon which position is selected will determine which combination of resistors are used. The liftgate module monitors the voltage level in the liftgate mode signal circuit, as each mode is selected, the voltage within the signal circuit incrementally drops. It is this method the liftgate module will determine the if mode switch is in the manual mode, the garage mode or the maximum open mode.
Conditions for Running the DTC
The system voltage is 9-16 V.
Conditions for Setting the DTC
The liftgate control module detects an out of range condition in the mode switch signal circuit.
Action Taken When the DTC Sets
The manual mode function and the garage mode function will be inoperative.
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.
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 (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, observe the scan tool Liftgate Mode Switch parameter while changing the mode switch between the Off and 3/4 positions. The value should vary from greater than 100 counts to less than 400 counts as the switch is changed.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the S45B liftgate control switch-interior.
2. Test for less than 30 ohm between the ground circuit terminal 1 and ground.
• If greater than the specified range, test the ground circuit for a open/high resistance.
3. Ignition ON, verify the scan tool Liftgate Mode Switch parameter is greater than 300 counts.
• If less than the specified range, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the K39 liftgate module.
4. Connect a 3A fused jumper wire between the signal circuit terminal 3 and ground, verify the scan tool Liftgate Mode Switch parameter is less than 5 counts.
• If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K39 liftgate module.
5. If all circuits test normal, test or replace the S45B liftgate control switch-interior.
Component Testing
1. Ignition OFF, disconnect the harness connector at the S45B liftgate control switch-interior.
2. Test for 0.6-0.8 ohm between the signal terminal 3 and the ground terminal 1 with the liftgate mode switch in the Off position.
• If not within the specified range, replace the S45B liftgate control switch-interior.
3. Test for 2-2.5 ohm between the signal terminal 3 and the ground terminal 1 with the liftgate mode switch in the Max position.
• If not within the specified range, replace the S45B liftgate control switch-interior
4. Test for 6-7 ohm between the signal terminal 3 and the ground terminal 1 with the liftgate mode switch in the 3/4 position.
• If not within the specified range, replace the S45B liftgate control switch-interior
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) Diagnostic Repair Verification after completing the repair.
* Rear Compartment Lid Release Switch Replacement (Rear Compartment Lid Release Switch Replacement)
* Control Module References (Programming and Relearning) for the liftgate module replacement, setup and programming