ABS & SERV lights on, MOT failed, can't clear it with the computer.. advice please

[chris79]

Ok, got the ABS and SERV lights on the dash.. it's just failed MOT for this.

Guy in the garage says the computer check is indicating a problem with the passenger side REAR wheel.. however he's tried clearing the codes off the ECU but the lights won't go out.

He says he then did a test where he jacked the car up and spun the wheel and it's getting a 'pulse' back, which indicates it's working ok?

Any ideas what may be the cause or where to go next?... on the one hand the test computer states a problem, but when testing it's indicating it's getting a signal back.

Thanks in advance!!

(Mk1 172 W-Reg)

 

[Fletcher]

Re: ABS & SERV lights on, MOT failed, can't clear it with the computer.. advice pleas

I was going to say maybe it's UCH releated, but IIRC the phase 1 doesn't have a UCH.

 

[ben lee]

Re: ABS & SERV lights on, MOT failed, can't clear it with the computer.. advice pleas

check the ring as if its cracked/damaged will still give you a reading but poss a faulty one.

 

[chris79]

Re: ABS & SERV lights on, MOT failed, can't clear it with the computer.. advice pleas

check the ring as if its cracked/damaged will still give you a reading but poss a faulty one.

Cheers will do, what does the ring look like could someone help describe what to look for? How is it fixed, is it part of the brake disk or something?

Cheers!

 

[chris79]

Re: ABS & SERV lights on, MOT failed, can't clear it with the computer.. advice pleas

Just to update my own thread here (in case anyone searches the same problem in the future)... I fixed the ABS + SERV light myself, the code was suggesting an open circuit on the passenger side rear ABS... so I took the wheel off and gave the sensor a good spray down with WD-40 ... put wheel back on and also had a bit of a wiggle of the wires from the ABS unit all the way up to the front of the car where it goes through the floor panel and under the passenger seat..

2 days later I got in the car to take it for MOT and after driving out my street the ABS + SERV lights went out.. \o/ ...

So it was either the WD-40 on the sensor or a wiggle of the wires.. not sure which.

 

[JSB101]

Re: ABS & SERV lights on, MOT failed, can't clear it with the computer.. advice pleas

I had this problem, had checked but couldn't find any problem with abs fault. After a couple of days the lights went out...!

Just to update my own thread here (in case anyone searches the same problem in the future)... I fixed the ABS + SERV light myself, the code was suggesting an open circuit on the passenger side rear ABS... so I took the wheel off and gave the sensor a good spray down with WD-40 ... put wheel back on and also had a bit of a wiggle of the wires from the ABS unit all the way up to the front of the car where it goes through the floor panel and under the passenger seat..

2 days later I got in the car to take it for MOT and after driving out my street the ABS + SERV lights went out.. \o/ ...

So it was either the WD-40 on the sensor or a wiggle of the wires.. not sure which.

 

[MicKPM]

Re: ABS & SERV lights on, MOT failed, can't clear it with the computer.. advice pleas

These cases are usually down to a corroded connection near the rear beam giving a poor sensor earth which the ABS ECM interprets as an open circuit.

 

[chris79]

Re: ABS & SERV lights on, MOT failed, can't clear it with the computer.. advice pleas

These cases are usually down to a corroded connection near the rear beam giving a poor sensor earth which the ABS ECM interprets as an open circuit.

Cheers, I'll be sure to check that one out if it comes back on!

 

[JSB101]

Re: ABS & SERV lights on, MOT failed, can't clear it with the computer.. advice pleas

Cheers for that MicKPM

These cases are usually down to a corroded connection near the rear beam giving a poor sensor earth which the ABS ECM interprets as an open circuit.