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 Descriptor

DTC C0407 02: AWD Oil Pump Motor Short to Ground
DTC C0407 04: AWD Oil Pump Motor Open
DTC C0407 0B: AWD Oil Pump Motor High Current
DTC C0407 64: AWD Oil Pump Motor Component Slipping

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Control | C0407 02 | C0407 04 | -- | C0407 0B, C0407 64
Low Reference | C0407 02 | C0407 04 | C0407 04 | C0407 02

Component | Condition | DTCs
--- | --- | ---
AWD Oil Pump Motor | Oil leak, oil pump defect | C0407 0B, C0407 64

### Circuit/System Description

The oil pump motor is installed in the torque transfer device housing. The rear differential clutch control module supplies battery voltage to the control circuit and ground to the low reference circuit of the oil pump motor. As soon as the engine is started the oil pump motor will be activated. The oil pump is running until the pressure of approximately 3200 kPa (464 PSI) is reached. The oil pump motor power consumption is the indicator for the oil pressure. The consumption is constant when the full system pressure is reached. The rear differential clutch control module shuts down the pump motor when the full system pressure is reached. Below approximately 2700 kPa (392 PSI) the pump motor will be restarted.

### Conditions for Running the DTC

#### C0407 02 and C0407 04

• | The ignition is ON.

• | The oil pump motor voltage is above 4.8 V.

#### C0407 0B

• | The ignition is ON.

• | The oil pump motor is running.

• | The oil temperature is above 0°C (32°F).

#### C0407 64

• | The ignition is ON

• | The oil pump motor voltage is above 11.5 V.

• | The oil temperature is above -20°C (-4°F).

### Conditions for Setting the DTC

#### C0407 02

The oil pump current is more than 9.0 A in 20 consecutive test cycles. The current will be retested every 30 s.

#### C0407 04

The oil pump current is less than 0.3 A for 30 s.

#### C0407 0B

The oil pump current is more than 7.0 A for 2 s in 10 consecutive test cycles.

#### C0407 64

The oil pump current is below a threshold at the end of a pump activation cycle in 30 consecutive test cycles. The measured current is less than 1.5 A from the threshold. The threshold is temperature dependent.

### Action Taken When the DTC Sets

#### C0407 02 and C0407 04

• | All-wheel drive (AWD) is disabled

• | Service AWD is displayed on the driver information center.

#### C0407 0B and C0407 64

An error report entry is stored, no further action is performed.

### Conditions for Clearing the DTC

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

• | The DTC is not detected in 40 consecutive power cycles.

### Reference Information

#### Schematic Reference

Rear Axle Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

All-Wheel Drive 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 diagnostic tester information

### Circuit/System Verification

Engine running, observe the scan tool Rear Differential Clutch Pump Motor Current parameter. The reading should be between 800-5000 mA when stationary.

### Circuit/System Testing

1. Ignition OFF, inspect for signs of damage of the wire, the oil pump motor and the housing.

⇒ | If a damage is visible, replace the appropriate component.

2. Replace the M32 Oil Pump Motor.
3. Ignition ON, verify the DTC does not reset.

⇒ | If the DTC resets, replace the K47 Rear Differential Clutch Control Module.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Differential Clutch Pump Replacement

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