Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	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	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Control	C0393 0B, C0408 02	C0408 04	--	C0408 61
Low Reference	-	C0408 04	-	-

Circuit/System Description

The limited slip 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 limited slip 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 limited slip differential clutch solenoid valve control circuit.

•	The rear differential clutch control module detects a current greater than 5.7 A on the limited slip 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 limited slip 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

Connector End View Reference

Component Connector End Views

Description and Operation

Rear Drive Axle Description and Operation

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References 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

Note

The torque transfer device 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 C and ground.

3.	If not the specified value, test the control circuit for a short to ground. If there is a short circuit to ground, replace the oil pump motor/wiring assembly M32. If the circuit test is normal, replace the solenoid valve of the rear axle clutch Q49.

4.	Test for 2-4 Ω between the control circuit terminal C and the ground reference circuit terminal D.

5.	If not within the specified range, replace the Q49 Rear Axle Coupling Solenoid Valve.

6.	Replace the K47 Rear Differential Clutch Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Limited Slip Differential Clutch Valve Replacement

•	Differential Clutch Pump Replacement

•	Control Module References for rear differential clutch control module replacement, setup, and programming