For 1990-2009 cars

### 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 Descriptors

DTC C0393 06: Rear Axle Coupling Solenoid Control Circuit
DTC C0393 0B: Rear Axle Coupling Solenoid Control Circuit Current Above Threshold

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
High Coupling Solenoid Control Circuit | C0393 06 | C0393 06 | -- | --
Low Coupling Solenoid Control Circuit | -- | -- | -- | C0393 0B

### Circuit/System Description

The coupling control module (CCM) provides a power and ground circuits to the coupling solenoid. The coupling solenoid receives current from the CCM and converts that into torque through the clutch to the rear tires.

### Conditions for Running the DTC

• | The ignition is ON.

• | Ignition voltage is greater than 9 volts.

### Conditions for Setting the DTC

• | An open is detected on the high or low coupling solenoid circuits.

• | A short to ground is detected on the high coupling solenoid circuit.

• | An over current is detected on the Solenoid circuit.

### Action Taken When the DTC Sets

One or more of the following actions may occur:

• | All Wheel Drive Off (AWD Disabled).

• | Service All Wheel Drive (Service AWD).

### Conditions for Clearing the DTC

• | The condition for the DTC is no longer present.

• | The DTC is not detected in 100 consecutive drive cycles.

### Reference Information

#### Schematic Reference

• | Rear Axle Schematics

• | Differential Lock Schematics

#### Connector End View Reference

Rear Axle Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Scan Tool Data List

### Circuit/System Verification

DTC C0393 will set as result of CCM Solenoid or circuit failure, test for power and ground circuits to the CCM.

⇒ | Repair the power or ground circuits.

### Circuit/System Testing

Important: It is recommend that Component Testing is performed before Circuit Testing when diagnosing the power vacuum booster Solenoid.

1. Ignition OFF, disconnect the 5 way harness connector at the CCM.
2. Test for less than 1 ohm between the ground circuit terminal and ground.

⇒ | If greater than 1 ohm, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the Battery circuit terminal and the ground circuit terminal.
4. Ignition ON, engine OFF. The test lamp should turn ON.

⇒ | If the test lamp is always ON, test the CCM circuits for an open or short to ground. If the circuit tests normal, replace the coupling control module (CCM).

⇒ | If the test lamp is always OFF, test the Battery circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the coupling solenoid.

### Repair Instructions

Perform the Diagnostic System Check - Vehicle after completing the diagnostic procedure.

• | Power Vacuum Brake Booster Replacement

• | Control Module References for CCM replacement, setup, and programming