OEM Part Numbers & Cross-References

Technical Specifications

Product Description

This is a refurbished original Siemens Haldex control unit with OEM number 1K0907554L, developed for second-generation Haldex AWD systems used in Volkswagen Group vehicles. The module manages rear axle engagement by controlling the hydraulic operation of the Haldex clutch and communicating with ABS / ESP and drivetrain systems.

What This Control Unit Does

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

A faulty Gen 2 Haldex ECU can cause total loss of rear drive, intermittent AWD operation, CAN communication errors, or ESP / ABS warning lights. This refurbished version is resealed with new silicone for durability comparable to a new module and is tested before dispatch.

Vehicle Compatibility

Common applications for this 2nd generation Haldex control unit include the following VAG AWD vehicles. Always confirm the part number on your old module before purchase:

Volkswagen

Audi

Škoda

SEAT

Common Diagnostic Fault Codes & Symptoms

Problems with the Haldex control unit can trigger communication faults, pump or valve faults, and dashboard warning lights. Common fault codes and symptoms include:

Installation & Recommended Service

Installation Notes

• Disconnect the battery and safely access the Haldex module on the rear differential
• Remove the old controller and inspect the connector pins and housing for corrosion or moisture
• Install the replacement ECU carefully and reconnect all plugs securely
• Clear fault codes and confirm AWD module communication with a suitable diagnostic tool
• Carry out coding or adaptation if required by the vehicle after installation

Recommended While Replacing the Unit

• Replace the Haldex control valve N373 when replacing the control unit
• Renew Haldex oil / service fluid
• Check the pump and connector condition before final installation
• Inspect the pre-charge pump and wiring
• Check for stored ABS / AWD communication faults after installation

Why Haldex Control Units Fail

1. Moisture Ingress & Corrosion

Water or condensation inside the module housing can damage the electronics and interrupt communication with the AWD system.

2. Pump or Valve Faults

Failures in the Haldex clutch pump or N373 valve can overload the ECU and trigger repeated drivetrain faults or rear axle disengagement.

3. Internal Electronic Failure

Age, vibration and temperature cycling can lead to internal circuit failure, memory errors and unstable AWD operation.

4. Wiring or Connector Problems

Corroded plugs, damaged wiring or weak power supply can create no-communication errors and unreliable AWD function.

Quality Assurance & Warranty

12-Month Warranty: This refurbished Haldex control unit is supplied with a 12-month warranty for the product itself and is tested before dispatch.

Warranty Includes

• Verified functionality of the controller hardware
• Bench-tested operation before shipping
• Basic pre-purchase compatibility guidance

Warranty Does Not Cover

• Incorrect part ordering without part-number verification
• Damage caused by wiring faults, moisture ingress or improper installation
• External pump, valve or vehicle-side electrical faults

Questions or Need Help?

If you have any questions about compatibility, diagnostics, or installation, contact us and we will help you choose the correct Haldex solution for your vehicle.

Important Purchase Information

• Please verify this module fits your specific vehicle before placing an order
• Worldwide shipping is available – if your country is not shown at checkout, contact us directly
• Replacing Haldex oil and checking the N373 valve is recommended when fitting a replacement ECU
• Online support is included if the module requires coding after installation