Software Incompatibility with Anti-Lock Brake System Control Module

Possible causes

• CommonThe anti-lock brake system (ABS) control module replaced but never programmed or coded to this vehicle
• CommonUsed module fitted from a different vehicle, model year or specification
• CommonSoftware update interrupted, often by battery voltage falling during programming
• CommonOne module updated while others were left at their old versions
• CommonWrong part number - brake modules vary by wheel size, market and options
• CommonCalibration or variant coding not performed after fitting
• RareCorrupted module software

What you might notice

• ABS, stability control and traction control warning lights on
• Anti-lock braking inoperative
• Electronic park brake not releasing or applying, on vehicles that use one
• Fault present since a repair or service visit
• Speedometer occasionally affected, since wheel speed often comes from this module

What to check, in order

1. Drive gently and allow much more stopping distance than usual. Nothing about the pedal feels different, which is exactly why it catches people out on the first hard stop.
2. Ask what was done recently. An ABS module, pump or steering angle sensor replacement immediately before this appeared is the explanation.
3. Read the module's software and part numbers against the vehicle's build specification.
4. Check whether the required calibration was done after fitting. Steering angle sensors in particular need a zero-point calibration, and skipping it produces exactly this.
5. Check the part number matches the vehicle's wheel size, market and option list - brake modules are not interchangeable across variants.
6. Do not replace the module again. This needs manufacturer-level programming, not different hardware.