Bmw abs stress

speedometer
abs
bmw
sensors
528

#1

Ok here we go! We have a 1999 BMW 520i with German Specs. Our ABS light is on and when we hook it up to the computer the code reads 59 30 120. We have had the rear right sensor changed but that has not fixed the problem. Here is the kicker. The light only comes on when the car is warm or hot. It won’t come on in the winter until the car has warmed up. While it’s on the odometer and speedometer does not function. Have at it folks!


#2

Just a wild guess it seems like a vehicle speed sensor is not registering the speed correctly which in turn illuminates the ABS light as the ABS computer cannot react to no speed input.


#3

My guess is that it’s a fault internal to the ABS module. I base this on the fact that the issue happens when the engine (and therefore the ABS module) is warm.


#4

I have no idea what those codes point to. However, I would go with andrew_j by the simple fact that the ABS light and dead speedometer go together. On many ABS systems the VSS is integral to monitoring the rear wheels. I don’t know about the BMW tho.


#5

Fix the speedo problem, which is probably the VSS, and see if the ABS problem disappears. I’ll bet a box of muffins it does.


#6

Isn’t the VSS on this car generated by the ABS controller, using the wheel speed sensors?


#7

You might be right, but I suspect it’s the other way around. I suspect the VSS feeds a signal to the ABS system for comparison to the wheel speed sensors.

Unfortunately, I no longer have access to Mitchell’s or Alldata to look it up.


#8

I see your muffins and raise you cupcakes!


#9

Thanks everyone,
I will give it a try. To change out the entire ABS system is going to be like 700 bucks and we don’t know if that is even the problem! The mechanic suggested that the speed and ABS are two separate issues. If I go with the VSS I think it will be a much better option and less expensive to fix. I will let you know if it worked.
Would it make sense to swap out ABS sensors with another car to see if it works first?