Differential front axle final drive. Porsche 958 Cayenne 3.0L / 3.0L Diesel / 3.0L Hybrid

Transfer Case Electric Servo Motor

The transfer-case electric servo motor — also called a transfer case/shift motor, actuator, or servomotor — is a compact electric actuator that controls the Cayenne’s transfer case. It adjusts the internal gearing and clutch positions, enabling all-wheel-drive engagement and managing the low/high reduction functions inside the transfer box. This part is sold under Porsche part number PAB-341-601 (superseded by 955-624-601-00 and 955-624-601-01).

Why Replace It ?

• A servo motor should be replaced if it fails to operate or communicate properly, or if it shows signs of electrical damage or corrosion. Common symptoms include:
• AWD warning lights in the instrument cluster
• Vehicle operating as 2WD instead of AWD
• Slow, noisy, or delayed engagement
• Clunks or unusual noises when slowing down
• Stored transfer-case diagnostic trouble codes (DTCs)
• Because the motor contains sensors (potentiometers) and the connector seals can deteriorate, many failures are electrical rather than purely mechanical.

• Porsche 955 Cayenne 3.2L V6 2003-06
• Porsche 955 Cayenne S 4.5L V8 2003-06
• Porsche 955 Cayenne Turbo 4.5L 2003-06
• Porsche 955 Cayenne Turbo S 4.5L 2006>>
• Porsche 957 Cayenne 3.0L Diesel 2007-10
• Porsche 957 Cayenne 3.6L 2007-10
• Porsche 957 Cayenne S/GTS 4.8L 2007-10
• Porsche 957 Cayenne Turbo / Turbo S 4.8L 2007-10  

Common Symptoms & Failure Signs of AWD Systems

• Dashboard Warnings: Messages like “All-wheel drive system defective” may appear, often accompanied by reduced or no AWD functionality.
• AWD Engagement Issues: Vehicle stuck in 2WD or transfer case fails to shift into longitudinal reduction.
• Drivetrain Noises: Clunks, slow engagement, or unusual sounds at low speeds, sometimes intermittent.
• Diagnostic Trouble Codes (DTCs)
• Common codes related to AWD/transfer case issues include:
• 2040: Voltage supply to transfer box servo motor
• 2041: Ground supply
• 2042: Activation
• 2039 / 2033: Other transfer case errors
• These codes typically prompt technicians to inspect the servo motor, wiring, and connector pins.
• Connector Corrosion & Moisture Issues
• Porsche technical bulletins note that the servo motor plug can allow moisture ingress, leading to corroded pins. Recommended solutions include:
• Repair kit (replacing a section of cable/plug)
• Full replacement of motor + cable, depending on damage
• Tip: Don’t assume the motor is faulty before checking connectors and wiring.
• Transfer Case Mechanical Wear
• Sometimes, noisy or slipping transfer cases are due to mechanical issues rather than the servo motor. Common problems include:
• Stretched chain
• Worn internal components
• These failures are especially common on higher-mileage Porsche 955/957 models. Always consider mechanical wear as a potential cause when diagnosing AWD problems.
• When replacing you will need a new ECU module to fit or reprogrammed 

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Diagram ref no 14