One of the latest Protips from German parts specialist febi highlights a common issue with certain BMW 1 series and 3 series models. This issue can be solved with a replacement ABS ring (febi 178022) which fits BMW 1 Series – E81, E82, E87, E88 and 3 Series – E90, E91, E92. 

The issue generally first appears when one or more of the following instrument warning lights are illuminated: ABS, traction control or brake light. The vehicle also has intermittent loss of power. 

febi recommends that using a suitable diagnostic tool, a technician should check for fault codes. However, these may be intermittent at the time of testing. Common codes are:  

• 5DC1 = RHR wheel speed sensor plausibility, ABS – DSC wheel speed sensor. 
• 5DB1 = RHR wheel speed sensor plausibility, ABS – DSC wheel speed sensor. 

The problem results from a corrosion build up behind the ABS reluctor ring causing distortion or fracturing. As such, the reluctor ring runs out of true and makes contact with the wheel speed sensor. The resulting lack of air gap causes the fault in the braking system and the warning lamp to illuminate. 

To solve the problem the technician should raise the vehicle, inspect the driveshaft for corrosion and remove the wheel on the side with the fault. They should then remove the 12-point (30 mm) hub nut, then undo the six E12 bolts fixing the driveshaft to the axle. Remove the driveshaft from the vehicle. Next, Inspect the driveshaft for excessive corrosion around the ABS reluctor ring. If the driveshaft is badly corroded it should be replaced. 

Alternatively, the technician can remove the damaged ABS reluctor ring, clean up the mating surface of the driveshaft where the reluctor ring fits, then install the new ABS reluctor ring (febi replacement part 178022). 

They should then remove the ABS sensor and check for wear or damage. Replace as necessary using febi part 32660 for vehicles without active steering, or 102856 for vehicles fitted with active steering. Next, refit or replace the driveshaft using a new hub nut (01701) and refit the driveshaft bolts making sure that they are tightened to the manufacturer’s specified torque setting.

Replacement driveshafts for each model are available from febi with the reluctor ring already fitted.

In this way febi can offer a complete and convenient solution to this common issue, with parts available from local motor factors. 

For complete information on all febi parts visit the Partsfinder online catalogue.