ABS pump

ABS and DSC pumps/modulators were a major problem in all of the E-Generation vehicles.

The units in F and G-Generation vehicles are also prone to failure, but to a much lesser extent—we assume that the manufactures resolved some critical design flaws.

Typically it is the module in these units that fail— but the pumps can wear out, and the solenoid valves can also leak or seize.

ABS and DSC pump/modulators are critical components of the ABS (Anti-lock Braking System) and DSC (Dynamic Stability Control) systems used by BMW.

The ABS system works to maintain tire traction with the road during braking—which it does by using the ABS pump to pulse the breaks when the car begins to lose traction. This prevents the vehicle from skidding and allows it to regain traction.

The DSC systems is a later and more advanced system—it represents a more holistic approach to vehicle stability, incorporating ABS along with additional sensors and control logic to monitor vehicle stability and traction. The DSC system is now standard in BMWs.

E-Generation

For E-Generation BMWs, second-hand ABS/DSC units cannot be matched using VIN/part number from the catalogue—as second-hand modules have specific firmware versions installed for the original car—and can’t be coded like new ones.

To match a second-hand unit to your BMW you must get the part numbers physically off your unit—and match them to the corresponding numbers on a replacement unit (they should be visible from the engine bay.) The particular part numbers depend on the manufacturer:

• BOSCH: For Bosch units, this will be the Bosch part number stamped into the alloy block starting with 02.
• ATE: For ATE units, you can match either the BMW or ATE number located on the white label, which is found on the pump (black cylinder.)

F-Generation and G-Generation

The later generation DSC pump/modulator units are built differently to their earlier counterparts. In most cases they can be matched by VIN but require some delicate coding with specialist software tools—ISTA or aftermarket tools like Autologic won’t suffice.

ABS/DSC pumps can interchange between vehicles, but in some cases it will make coding more difficult—we approach this on a case-by-case basis.