E39 Wheel Speed Sensor? Speedo, ABS, Traction Control N/OK
Discussion
Yesterday as I was leaving work I felt a crunch from some ice on my wheels, then my ABS and Traction Control warning lights both flashed up and my speedo, MPG and mileage counter have all also stopped working - my best guess from a quick skim on the forums is that the wheel speed sensor has gone - although the fuel gauge is also being temperamental.
I rang a local independent garage, who I trust, who said it's likely the wire has come loose or the sensor has broken which is a big job to get it out and replaced (something about drilling the sensor out?). He suggested to check the cable and leave it as it may clear itself, otherwise he wont be able to see the car for a week or so. However, I had a look last night and the wire to the sensor is still secured in place, as far as I can tell.
Without a full diagnostic I cant be sure if the sensor does need replacing, does anyone have any suggestions as to ruling out any other causes before sending the car to have the "big job" done?
E39 520i Touring SE.
I rang a local independent garage, who I trust, who said it's likely the wire has come loose or the sensor has broken which is a big job to get it out and replaced (something about drilling the sensor out?). He suggested to check the cable and leave it as it may clear itself, otherwise he wont be able to see the car for a week or so. However, I had a look last night and the wire to the sensor is still secured in place, as far as I can tell.
Without a full diagnostic I cant be sure if the sensor does need replacing, does anyone have any suggestions as to ruling out any other causes before sending the car to have the "big job" done?
E39 520i Touring SE.
2 likely candidates.
Wheel sensor, they don't all need drilling but they can, it isn't a big job either way, just bigger by 10/15 min if they heed drilling out.
ABS ECU/Pump/Solenoid pack, different scenario & as they directly sit on the canbus they can affect other things that also rely on canbus comms.
Not sure if one of these is the fuel gauge but it could be, or it could just be coincidence.
Wheel sensor, they don't all need drilling but they can, it isn't a big job either way, just bigger by 10/15 min if they heed drilling out.
ABS ECU/Pump/Solenoid pack, different scenario & as they directly sit on the canbus they can affect other things that also rely on canbus comms.
Not sure if one of these is the fuel gauge but it could be, or it could just be coincidence.
When removing the wheel speed sensors, check for wear on the face of the sensor. If you find this to be the problem, there is a simple solution:
There is only a very small gap (approx. 0.25-0.5mm) between the reading face of the sensor and the reluctor ring which is wrapped around the axle shaft. A common problem on many BMW's is corrosion of the axle shaft which causes the diameter of the reluctor to increase slightly, this closes the gap and wears the face of the sensor until it fails.
An easy fix is to put some shim or a washer in between the sensor and the mounting face to account for the wear. On my car I had this problem on both sides on the rear axel. I measured wear of 0.5mm and knew the gap should be around 0.25mm. So I used an M5 washer which was 0.8mm thick to space the sensor out slightly. Worked a treat & saved £750 a side for replacement axels!
There is only a very small gap (approx. 0.25-0.5mm) between the reading face of the sensor and the reluctor ring which is wrapped around the axle shaft. A common problem on many BMW's is corrosion of the axle shaft which causes the diameter of the reluctor to increase slightly, this closes the gap and wears the face of the sensor until it fails.
An easy fix is to put some shim or a washer in between the sensor and the mounting face to account for the wear. On my car I had this problem on both sides on the rear axel. I measured wear of 0.5mm and knew the gap should be around 0.25mm. So I used an M5 washer which was 0.8mm thick to space the sensor out slightly. Worked a treat & saved £750 a side for replacement axels!
Bit random but my Z4 did something similar ish and seemed to be going haywire with abs/DSC etc.
It needed new front discs/pads, but upon replacing a day or two later it was clear pad material had come away from the pad backing plate and bits were loose and jamming a bit.
Reset it all via inpa and it was then fine.
So double check discs/pads/calipers are all free and in good condition.
It needed new front discs/pads, but upon replacing a day or two later it was clear pad material had come away from the pad backing plate and bits were loose and jamming a bit.
Reset it all via inpa and it was then fine.
So double check discs/pads/calipers are all free and in good condition.
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