Compatible OEM Part Numbers

Technical Specifications

Product Description

This is a genuine used original BorgWarner Haldex 5th generation control unit with part number 0CQ907554D. It functions as the electronic management module of the rear AWD coupling system, responsible for activating and regulating the rear differential clutch pack in response to traction demands and driving conditions.

What This Control Unit Does

• Continuously monitors rotational speed differences between front and rear axles
• Operates the hydraulic pump to generate and regulate clutch pack pressure
• Engages rear-wheel drive distribution automatically when required
• Exchanges data with ABS, ESP and engine management control modules
• Stores and applies learned pump calibration values for accurate pressure control
• Protects the coupling from thermal overload via temperature monitoring

The 0CQ907554D with hardware HW H52 and software SW 7081 is used across a wide range of VAG group vehicles. Always verify the part number on your existing unit before ordering.

Vehicle Compatibility

The 0CQ907554D is compatible with VAG group vehicles equipped with Haldex 5th generation AWD systems. Typical applications include the models below. Always verify the part number on your existing unit:

Volkswagen

Audi

Škoda

SEAT

Common Diagnostic Fault Codes

A defective Haldex control unit commonly triggers one or more of the following fault codes. If your vehicle displays any of these, the control unit may require replacement:

Installation & Calibration

Installation Steps

• Locate the Haldex control unit mounted on the rear differential / rear axle assembly
• Disconnect the electrical connector and remove all mounting fasteners
• Carefully remove the old control unit from the coupling housing
• Position the replacement unit and secure all mounting points
• Reconnect all electrical connectors and verify secure fitment
• Connect a VAG-compatible diagnostic tool and code the unit to the vehicle
• Run Pump Learn function via module 22 Basic Settings (engine must be running)
• Carry out a short test drive and confirm AWD engagement using the diagnostic tool

Pump Learn – Mandatory After Installation

The Pump Learn calibration procedure is required every time a Haldex control unit is replaced or reinstalled. Without completing this step, the unit will not deliver sufficient power to the pump motor, which prevents AWD engagement. Navigate to module 22 AWD in VCDS or ODIS → Basic Settings → select Pump Motor calibration. The procedure takes approximately 1 minute and must be performed with the engine running.

Recommended Maintenance at Time of Installation

• Replace Haldex oil at the same time as fitting the new control unit
• Clean the pump gauze strainer with compressed air or brake cleaner
• Inspect the 6-pin wiring connector located under the rear seat access panel
• Check both 12V supply fuses dedicated to the Haldex AWD system
• Clear all stored diagnostic fault codes after installation and perform a test drive

Why Haldex Control Units Fail

1. Water Ingress & Corrosion

The control unit is located near the rear axle in an exposed position. Over time, moisture can penetrate the housing, corroding the internal circuit board and causing communication failures or complete loss of AWD function.

2. Power Supply Faults

The Gen 5 Haldex system relies on two independent 12V supply lines, each protected by a separate fuse. Blown fuses, corroded pins, or damaged wiring at the rear connector block are a common cause of total AWD loss, often without any obvious warning light on the dashboard.

3. Thermal Stress

Extended high-load driving, repeated AWD engagement, or engine remapping can generate excessive heat that degrades solder joints and internal electronic components within the control unit over time.

4. Neglected Haldex Oil

Old or contaminated Haldex fluid leaves deposits that clog the pump gauze and internal hydraulic passages. This accelerates wear on the pump and can cause inaccurate control unit readings, leading to incorrect pump calibration and eventual AWD failure.

Quality Assurance & Warranty

12-Month Warranty: This used Haldex control unit has been fully tested and is covered by a 12-month warranty against functional defects under normal operating conditions.

Warranty Coverage Includes:

• Electronic control unit malfunctions
• Communication failures with AWD, ABS or ESP modules
• Pump control circuit defects
• Internal calibration memory errors

Warranty Exclusions: Damage resulting from incorrect installation, failure to perform the mandatory Pump Learn calibration, incompatible vehicle fitment, external electrical faults, or physical damage during handling.

Questions or Need Help?

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

Important Purchase Information