• 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.

The power transfer unit shift actuator sensor is to monitor the position of the power transfer unit actuator. The sensor is a three wire circuit that consists of a 5 V reference, low reference, and signal low circuit.

The engine is running.

The rear differential clutch control module detects a short to battery on the power transfer unit shift actuator position sensor circuit.

The rear differential clutch control module detects a short to ground on the power transfer unit shift actuator position sensor circuit.

The rear differential clutch control module detects a open on the power transfer unit shift actuator position sensor circuit.

The rear differential clutch control module detects a short to battery on the power transfer unit shift actuator position sensor circuit.

The rear differential clutch control module detects a short to ground on the power transfer unit shift actuator position sensor circuit.

The rear differential clutch control module detects a open on the power transfer unit shift actuator position sensor circuit.

The rear differential clutch control module detects that the power transfer unit shift actuator position sensor signal has incorrect frequency .

The rear differential clutch control module detects that the power transfer unit shift actuator position sensor signal is out of range.

One or more of the following actions may occur:

• The electronic limited slip system is disabled for the duration of the key cycle.
• The AWD SERVICE message is displayed in the driver information center.

• The condition for the DTC is no longer present.
• The DTC is not detected in 40 consecutive drive cycles.

Rear Axle Schematics

Master Electrical Component List

Rear Drive Axle Description and Operation

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

1. Ignition OFF and all vehicle systems OFF, disconnect the X2 harness connector at the M115 Power Transfer Unit Shift Actuator. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 Ω between the low reference circuit terminal 3 and ground.
• If 10 Ω or greater
1. Ignition OFF, disconnect the X1 harness connector at the K47 Rear Differential Clutch Control Module.
2. Test for less than 2 Ω in the low reference circuit end to end.
• If 2 Ω or greater, repair the open/high resistance in the circuit.
• If less than 2 Ω, replace the K47 Rear Differential Clutch Control Module.
• If less than 10 Ω
3. Ignition ON/Vehicle In Service Mode.
4. Test for 4.8–5.2 V between the 5 V reference circuit terminal 2 and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the X1 harness connector at the K47 Rear Differential Clutch Control Module.
2. Test for infinite resistance between the 5 V reference circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Ω in the 5 V reference circuit end to end.
• If 2 Ω or greater, repair the open/high resistance in the circuit.
• If less than 2 Ω, replace the K47 Rear Differential Clutch Control Module.
• If greater than 5.2 V
1. Ignition OFF, disconnect the X1 harness connector at the K47 Rear Differential Clutch Control Module, ignition ON/Vehicle In Service Mode.
2. Test for less than 1 V between the 5 V reference circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K47 Rear Differential Clutch Control Module.
• If between 4.8–5.2 V
5. Ignition ON/Vehicle In Service Mode.
6. Test for 4.6–5.6 V between the signal circuit terminal 1 and ground.
• If less than 4.6 V
1. Ignition OFF, disconnect the X1 harness connector at the K47 Rear Differential Clutch Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Ω in the signal circuit end to end.
• If 2 Ω or greater, repair the open/high resistance in the circuit.
• If less than 2 Ω, replace the K47 Rear Differential Clutch Control Module.
• If greater than 5.6 V
1. Ignition OFF, disconnect the X1 harness connector at the K47 Rear Differential Clutch Control Module, ignition ON/Vehicle In Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K47 Rear Differential Clutch Control Module.
• If between 4.6–5.6 V
7. Test or replace the M115 Power Transfer Unit Shift Actuator.
8. Operate the vehicle under the conditions for setting the DTC, the DTC should not set.
• If the DTC sets

  Replace the K47 Rear Differential Clutch Control Module.

• If the DTC doesn’t set
9. All OK.

1. Ignition OFF, disconnect the harness X1 connector at the M115 Power Transfer Unit Shift Actuator.
2. Install a 20 A fused jumper wire between the control terminal 2 and 12 V. Install a jumper wire between the low reference terminal 1 and ground.
3. Verify the power transfer unit clutch motor turns ON and OFF
• If the power transfer unit clutch motor does not turn ON and OFF

  Replace the M115 Power Transfer Unit Shift Actuator.

• If the power transfer unit clutch motor does turn ON and OFF
4. All OK

Perform the Diagnostic Repair Verification after completing the repair.

• Power Transfer Unit Case Replacement for M115 Power Transfer Unit Shift Actuator
• Control Module References for control module replacement, programming, and setup.