C0393

DTC C0393

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 C0393 0B
- Rear Axle Coupling Solenoid Valve Control Circuit High Current

Diagnostic Fault Information





Circuit/System Description

The rear differential clutch solenoid valve is mounted on the rear of the differential housing. The rear differential clutch control module supplies battery voltage to the control circuit and ground to the low reference circuit of the solenoid valve. The solenoid valve is controlled by a pulse width modulation (PWM) signal. The solenoid valve controls the hydraulic pressure to the clutch package of the rear differential. The locking level of the limited slip differential depends on the engagement of the clutch package.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

* The rear differential clutch control module detects a short to ground on the rear differential clutch solenoid valve control circuit.
* The rear differential clutch control module detects a current greater than 5.7 A on the rear differential clutch solenoid valve control circuit.

Action Taken When the DTC Sets

One or more of the following actions may occur:

* All-wheel drive (AWD) is disabled.
* Service Rear Axle is displayed on the driver information center.

Conditions for Clearing the DTC

* The condition for setting the DTC is no longer present.
* The DTC is not detected in 40 consecutive ignition cycles.

Diagnostic Aids

The rear differential clutch solenoid valve harness and differential clutch pump motor harness are all one assembly as part of the differential clutch pump motor. These harnesses should not be repaired and should be replaced if a wiring condition exists.

Reference Information
Schematic Reference

Rear Axle Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Rear Drive Axle Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Engine running, observe the scan tool Rear Differential Clutch Status parameter. The scan tool should display NORMAL when stationary.

Circuit/System Testing

Important: The rear drive clutch solenoid valve is calibrated with and is part of the rear differential clutch control module. Both components must be replaced as a matched set.


1. Ignition OFF, disconnect the X2 harness connector at the K47 rear differential clutch control module.
2. Test for a infinite resistance between the control circuit terminal 3 and ground.

• If not the specified value, test the control circuit for a short to ground. If a short to ground is present, replace the M32 oil pump motor/harness assembly. If the circuit tests normal, replace the Q49 rear differential clutch solenoid valve.

3. Test for 2-4 ohm between the control circuit terminal 3 and the ground reference circuit terminal 4.

• If not within the specified range, replace the Q49 rear differential clutch solenoid valve.

4. Replace the K47 rear differential clutch control module.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Limited Slip Differential Clutch Valve Replacement ()
* Differential Clutch Pump Replacement (Differential Clutch Pump Replacement)
* Control Module References (Programming and Relearning) for rear differential clutch control module replacement, setup, and programming