Operation CHARM: Car repair manuals for everyone.
Home >> Cadillac Truck >> 2010 >> SRX FWD V6-3.0L >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> B Code Charts >> B396D

B396D




Liftgate Interior Release Open/Close Switch Malfunction - DTC B396C or B396D

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 B396C 08
- Liftgate Mode Switch Circuit Performance Signal Invalid

DTC B396D 02
- Front Liftgate Actuator Switch Circuit Short To Ground

Diagnostic Fault Information





Circuit/System Description

The interior liftgate rotary 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 if mode switch is in the manual mode, garage mode or the maximum open mode.

The interior liftgate control switch has of a push button switch to command the liftgate to open and close. The liftgate module monitors the voltage level on the open/close signal circuit, when the switch is not being pressed the voltage level is at the system voltage. When the switch is pressed a contact within the interior liftgate control switch closes providing a ground path for the signal circuit causing the voltage level to drop to near zero volts. The liftgate module will detect the voltage drop and will then command the liftgate to open or close depending upon the current state of the liftgate at the time the switch is pressed.

Conditions for Running the DTC

The system voltage is 9-16 V.

Conditions for Setting the DTC

B396C 08

The liftgate control module detects an out of range condition in the mode switch signal circuit.

B396D 02

The liftgate control module detects a short to ground in the rear liftgate open/close switch signal circuit for greater than 60 seconds.

Action Taken When the DTC Sets

B396C 08

The manual mode function and the garage mode function will be inoperative.

B396D 02

The liftgate module will ignore the switch input from the interior liftgate control switch and the liftgate operations will only be available from the liftgate switches located on the liftgate panel or by an open or close request from the remote control keyless entry module.

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.

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. Ignition ON, verify the scan tool Liftgate Mode Switch parameter changes from 125 counts to 350 counts to 245 counts while rotating the S45B liftgate control switch - interior.

• If the value does not change with each position selected, refer to OFF/ 3/4 position/MAX Switch Circuit Test

2. Place the S45B liftgate control switch - interior to the OFF position.
3. Observe the scan tool Liftgate Front Control Switch parameter while pressing and releasing the liftgate button on the S45B liftgate control switch-interior. The parameter should change between Inactive and Active.

• If the value does not change, refer to Open/Close Switch Circuit Test

Circuit/System Testing

OFF/ 3/4 position/MAX Switch Circuit Test
1. Ignition OFF, disconnect the harness connector at the S45B liftgate control switch-interior.
2. Test for less than 10 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. Install 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.

Open/Close Switch Circuit Test
1. Ignition OFF, disconnect the harness connector at the S45B liftgate control switch-interior.
2. Test for less than 10 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 Front Control Switch parameter is Inactive.

• If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the K39 liftgate control module.

4. Install a 3 A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool Liftgate Front Control Switch parameter is Active.

• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K39 liftgate control 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 the values listed below between the signal terminal 3 and the ground terminal 1.

* 600-650 ohm in the Off position
* 125k-140k ohm in the 3/4 position
* 400k-415k ohm in the Max position

• If not within the specified ranges, replace the S45B liftgate control switch-interior.

3. Test for infinite resistance between the signal terminal 4 and the ground terminal 1 with the switch open.

• If not the specified value, replace the S45B liftgate control switch-interior.

4. Test for less than 3 ohm between the signal terminal 4 and the ground terminal 1 with the switch closed.

• If greater than the specified range, replace the S45B liftgate control switch-interior.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.

* Liftgate Actuator Control Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for the liftgate control module replacement, setup and programming

pro multis · About Operation CHARM