I upgraded my rear trailing arms to the R56 components and right off the get go I had the ABS trifecta.

Figured it was the ABS sensor and since they are different from R53 I ordered one.

The new sensor didn’t fix it so my son, a master mechanic, ohmed everything out and tested the wiring. Even changed the hub since the condition was unknown.

Long story short, the only thing that fixed it was taking the working sensor from left rear and swapping it with the non-working sensor on the right.

My car is a happy camper now. Not sure why. Did notice that there was no backing plates on my trailing arms but my son’s has backing plates. (Nothing to do with problem)

Just wondering if anyone had a similar issue.

 

Decided to go out for a drive and 10 miles up the road, bam...Trifecta again.

Waiting to read codes to see if problem followed.

 

Code says right rear abs sensor again. Scanned the speeds and the right rear jumps randomly from 5-8 kph but as much as 30! The speedometer also shows the corresponding speed while sitting still.

Drove is and the abs shows jumps and peaks which correspond to the abs kicking in on light braking.

Read where tach can cause this so I reinstalled the single tach and kombi and it didn’t fix the problem.

Any ideas?

 

Update #3

i tried putting int the original kombi and it didn’t fix it. Slaved in another abs module and my problem went away (RR showing speed at a stop and speedo bouncing at idle).
Going to change abs module and will report back.

 

ABS module fixed it (electronic side). No bounce on speedometer and no abs activation in the pedal.