Fault codes

[rodstir]

Hi

I have the following codes showing on my
X5 E70 2009 3.0sd

5E4E Wheel speed sensor front right supply
A0B5 Road speed signal fault
51B0 Message from DSC (brake-light switch/brake pressure) implausible

Has any one seen these before thinking the first 2 are connected but not sure about the third??

Any one know where the wheel sensor is supplied from???

Thanks

Rodstir

[kkodal78]

sounds like the abs sensor is either failed or dirty..


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[x555]

Agreed with above. Akso known as a pulse generator

[rodstir]

Thanks for that guys

I will do some investigating and see what I can find 

Rodstir

[rodstir]

Hi Guys

Does anyone know of away to test the ABS sensor ??????

[X5Sport]

I'm not certain how the system actually runs, but I believe the sensor sends a pulse train to the car caused by a signal generated by the ring of magnets passing the sensor.  The ABS computers count the pulses from the wheel sensors and detect a variation in one that signals a skid.  Looks like your front right is down.

If you have access to a meter capable of reading very low voltages or currents and a magnet you might be able to detect a very low current or voltage if a magnet is waved quickly (or if you spin the wheel) in front of the detector. 

You are looking for very small signals though so it might not be very easy.  If you have access to an oscilloscope then it's much easier as you should see the digital pulse train when you spin the wheel.

[rodstir]

Hi

I have now found that the DSC unit is faulty !!!!!!!! has anyone removed one of these before ????? do i need to take the whole unit off or can the unit be split in situ and leave the brake pipes alone ????? fingers crossed someone can help 

[Rusty]

[quote="X5Sport"]
I'm not certain how the system actually runs, but I believe the sensor sends a pulse train to the car caused by a signal generated by the ring of magnets passing the sensor.
[/quote]
The sensor is a capacitive type AFAIK.  They would not fit magnets to the ABS ring - imagine the build up of ferrous crud

[shadrack]

[quote="rodstir"]
Hi

I have now found that the DSC unit is faulty !!!!!!!! has anyone removed one of these before ????? do i need to take the whole unit off or can the unit be split in situ and leave the brake pipes alone ????? fingers crossed someone can help 
[/quote]

how did you find that out?

[rodstir]

Hi

As I was receiving fault codes for the O/S front wheel supply failure I traced the wires back to the unit confirming pins 12 and 26 if I remember correctly. I then checked continuity through the wires and sensor and took a reading from the back of the plug with the engine running. I then did the same for the N/S and found the there was a reading of 13.1 volts to the N/S wheel sensor but nothing to the O/S. So this makes me think that there is a fault in the unit and nothing to do with the sensor!!!!!!!!!