OEM Part Numbers

Technical Specifications

Product Description

This is a refurbished original Siemens Haldex control unit with OEM number 1K0907554B, developed for second-generation Haldex AWD systems used in Volkswagen Group vehicles. The module controls rear axle engagement, manages clutch pressure strategy and communicates with ABS / ESP and drivetrain systems.

What This Control Unit Does

• Controls the Haldex coupling for rear-wheel engagement on demand
• Communicates with ABS / ESP and drivetrain modules
• Monitors system operation and stores diagnostic trouble codes
• Controls pre-charge pump activation and clutch pressure strategy
• Helps restore stable AWD function in low-traction conditions

Vehicle Compatibility

Typical applications for this Gen 2 Haldex control unit include the following vehicles. Always confirm the part number on your original module before ordering.

Volkswagen

Audi

Škoda

SEAT

Common Symptoms of a Faulty Module

A faulty Haldex control unit can trigger fault codes, communication problems and complete loss of rear-wheel engagement. Typical symptoms include:

Installation

Installation Notes

• Disconnect the battery and access the rear differential Haldex module safely
• Remove the old control unit and inspect connectors for corrosion or moisture
• Install the replacement ECU carefully and reconnect all plugs securely
• Clear fault codes and confirm AWD communication with a diagnostic tool
• Carry out coding or adaptation if requested by the vehicle

Recommended Service Items

• Check or replace the Haldex control valve N373 if faulty
• Inspect the pre-charge pump and related wiring
• Renew Haldex oil / service fluid
• Perform a test drive and confirm correct AWD engagement

Why Haldex Control Units Fail

1. Water Ingress & Sealing Failure

Moisture, worn seals and housing contamination can affect the control unit electronics, leading to corrosion, unstable communication and complete AWD malfunction.

2. Valve or Pump Related Faults

Failure of the Haldex control valve N373 or pump can overload the AWD system and trigger recurring module-related diagnostic errors, communication faults or loss of rear axle engagement.

3. Internal Electronic Failure

EEPROM faults, internal memory errors and circuit-board wear can cause intermittent operation, no communication faults or complete loss of rear differential control.

4. Wiring or Power Supply Problems

Damaged wiring, poor terminal contact or unstable power supply can interrupt module operation and create misleading communication or actuator fault codes.

Warranty

12-Month Warranty: This refurbished Haldex control unit has been tested for correct operation and is supplied with a 12-month warranty under normal operating conditions.

Warranty Coverage Includes:

• Internal control unit malfunction
• Communication failures caused by the module itself
• Faults related to internal memory or controller operation

Warranty Exclusions:

• Incorrect installation or incompatible vehicle fitment
• External wiring, valve or drivetrain faults
• Physical damage, water damage after installation or mishandling

Questions or Need Help?

Our technical team is ready to assist with compatibility checks, installation guidance and coding support.

Important Purchase Information