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DTC C0393

DTC C0393

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 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 modulated signal (PWM-signal). The solenoid valve controls the hydraulic pressure to the rear differential clutch pack. 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

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


1. Engine running, vehicle stationary.

2. Verify that the status parameter for the rear differential clutch on the scan tool shows NORMAL.

3. If the parameter does not show NORMAL, see Test of circuit/system below.

4. If the parameter shows NORMAL:

Everything is OK


Circuit/System Testing

Note

Q48 The rear drive clutch solenoid valve is calibrated with and is part of the K47 Rear differential clutch control module. Both components must be replaced as a matched set.



1. With the ignition OFF, loosen connector X2 from the rear differential clutch control module K47 and Q49 rear differential clutch solenoid valve.

2. Test for a infinite resistance between the control circuit terminal B and ground.

3. If the value is less than that specified

Replace oil pump motor/harness assembly M32

check to see if there is a short to ground on the control circuit. 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.

4. If the value is infinite:

5. Test for 2-4 Ω between the control circuit terminal and the low reference circuit terminal on Q49 rear differential clutch's solenoid valve.

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

7. If the value is 2-4 Ω

Replace Q49 rear differential clutch solenoid valve and rear differential clutch control module K47.


Component test


Static test

1. Test for 2-4 Ω between the control circuit terminal and the low reference circuit terminal on Q49 rear differential clutch's solenoid valve.

2. If the value is not 2-4 Ω

Replace the Q49 rear differential clutch solenoid valve.

3. If the value is 2-4 Ω:

Everything is OK


Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.


• Limited Slip Differential Clutch Valve Replacement

• Differential Clutch Pump Replacement

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