BMW Mini TRW ABS Pump Repair: Warning Lights, Codes, Part Numbers and Refit

This page deals with the TRW unit alone. The other ABS units fitted to the car are covered on our Mini ABS pump and module repair page, and both sit within our wider range of ABS pump and ECU repairs.

Is the TRW unit behind your Mini’s ABS and traction lights?

The first sign is usually two amber lamps rather than one. The TRW module runs the anti-lock braking and also supplies the wheel-speed information that traction control depends on, so when the module develops a fault, both systems stand down at the same moment.

These are the faults that bring Mini TRW units to us:

• the ABS warning lamp on, and staying on
• the traction control lamp lit alongside it
• no communication, where a diagnostic tool cannot reach the ABS module at all
• wheel-speed sensor faults stored in the module’s memory
• reduced anti-lock support under hard braking

One lamp and one wheel-speed code, with everything else normal, is a different picture. The sensor or its wiring is the likelier culprit there, and our wheel speed sensor guide covers that check. Suspicion moves to the TRW unit when the sensors test sound and the code keeps coming back, or when the module vanishes from the diagnostic network altogether.

While the ABS lamp is lit, normal braking usually remains and the Mini will still pull up. What has gone is the anti-lock and traction assistance — the help that counts most on a wet road or in an emergency stop — so get the car checked promptly rather than driving round the warning. Our explainer on how an ABS pump works shows what the unit is doing when all is well.

There is an MOT consequence as well. The DVSA treats an ABS warning lamp that stays on after the start-up check as a major defect on any vehicle first used on or after 1 July 2003, and that includes any Mini on our list registered from that date.

Which codes does a failing TRW module leave on a scan?

Different scan tools describe the same fault in different words, so read the table as a guide to the pattern rather than a dictionary. These are the readings that point towards the TRW unit, and the limit of what each one proves.

If your scan shows 5DF0 or 5DF1 instead, those two codes are explained on our Mini ABS repair page.

Before a silent module is condemned, the car’s side of the connection has to be cleared. A tired battery, a poor earth or a damaged loom can cut the module off without anything being wrong inside it, and our guide to ABS module communication faults sets out which to look at first.

What wears a TRW ABS unit out, and why does it pass for a sensor fault?

The unit lives in the engine bay, plumbed into the brake lines. Every drive heats it and lets it cool again, every road surface shakes it, and the pump runs each time the anti-lock or traction control steps in. Around it, the brake fluid ages and takes on moisture unless it is changed on schedule.

None of that is unusual. What makes it tell on a Mini is time: the cars on our list were built between 2001 and 2013, so every one of these units has lived through a great many heat cycles and a lot of road. That is why the TRW unit is a common failing part on these cars rather than a rare one.

It passes for other faults because the module is where every wheel-speed signal is read and judged. As the module itself degrades, it can start rejecting readings from sensors that are perfectly healthy — which is why wheel-speed sensor faults sit on this unit’s list of common faults, and how a car can end up with new sensors and the same lamps lit.

A module on its way out can also stop answering the diagnostic tool entirely. That looks exactly like a wiring fault until the wiring is proved sound, and it is the other route by which the unit gets overlooked.

Is your Mini’s ABS unit the TRW one? Check the part number

Not every Mini carries the same ABS unit. The car used more than one supplier’s hardware over its life, and our Mini ABS page covers the others. The application list below shows the Minis this TRW unit is fitted to. It is not a complete list, so a model missing from it is no reason to rule the unit out.

The model narrows it down; the label on the unit settles it. These are the common part numbers for the TRW unit on these cars, grouped by how they begin so you can match your label quickly.

A number missing from this table is not a no. Give it to us on the repair form or through our contact page, and we will check it before anyone unbolts the unit.

Repairing the TRW unit or buying another: what changes at refit?

A new or used replacement puts a working unit on the car, but it arrives with none of your Mini’s configuration. Replacement ABS pumps on these cars require coding before the system will accept them, and that is a job for dealer-level diagnostic equipment.

Keeping your own unit also removes the matching problem. The part number that came off the car is the part number that goes back on, so there is nothing to cross-reference and nothing to configure.

What happens between removal and refit?

We work on the unit, not the car. This is how it reaches us and how it comes back.

1. Match the label before it comes off

   The repair form asks for the Mini’s details, the lamps showing, any scan readings and the number on the unit’s label. We confirm it is the TRW unit before your garage removes anything.

2. Removal at your garage, then the post

   Your garage takes the unit off and sends it in, well wrapped and with the pipe ports sealed so nothing gets inside.

3. Tested as it arrived

   The fault has to show itself on our test equipment before any work begins, so the repair rests on what the unit does, not on a code alone.

4. Rebuilt with new genuine components

   The unit is rebuilt to OE specification, then programmed and checked with dealer-level diagnostic tools before it is dispatched.

5. Refit, bleed and clear

   It goes back on without coding. The brake circuit was opened to take it off, so your garage bleeds the brakes, clears the stored codes and checks that the lamps go out.

Fitting can be part of the job too. We offer a professional fitting service where it is needed, arranged through our contact page.

TRW ABS pump questions from Mini owners