Abs, traction control and servo light on...help needed!!

[tonyd106]

As title says i have these 3 lights on, i've had my mate come round and plug his machine in and it said i have a faulty sensor on the o/s rear.

I had a quick look lastnight but didn't really see anything that looked wrong :S

Can anyone suggest anything or even post a picture off what maybe broke?

Thanks in advance.

 

[MicKPM]

What description did it give other than "O/S/R Sensor fucked"... Cohernace issues or target not recognised? You will need to look at the wheel again i'm afraid and you may also need the machine or an oscillescope to hand.

Firstly, get the vehicle jacked up on that corner and wheel off.
Secondly, inspect the sensor wiring, general condition of the sensor itself and most importantly the "reluctor ring" paying close attention when looking for signs of cracks (You will need to rotate the road wheel to inspecting the full rolling radius).

If the reluctor ring target is cracked it will need replacing which on the Clio II means replacement of the rear disc assembly as the rings can no longer be purchased on there own and they're shrink fit items also making htem tricky to fit for the average DIYer without gas bottles. Then, if all is well with the rings connect the diags or oscillescope and look at the sensor in questions live data output. Does the sensor detect rotation when the wheel is turned? If so, how does the graph or indicated wheel speed look? It should be progressive and smooth with no sudden jumps in value. If you see no movement disconnect the sensor and inspect the multiplug pins... if they're correded up to hell clean then with a small wire brush and loads of contact cleaner, replace and re-try the function test. If all is well with the pin condition replace the sensor.

Mick

 

[tonyd106]

Thanks alot mick i'll get it back in the air later and have a proper look at it all.

 

[Tigger]

I had this for a few weeks - checked all my brakes & abs rings all was ok. Came on again after fitting new rear pads, goodridge hoses and fresh fluid, thought it was a bit odd :S

Replaced my brake pedal switch (after trying the fix in the guide on here) ALL IS FINE

 

[MicKPM]

A brake pedal switch would've given its own fault code though IF it was responsible and most times its rare the switch actually needs replacing. He's seeing a fault code specifically relating to the OFR wheel

 

[tonyd106]

I did try getting to it but the torx didn't want to come undone

 

[shumoboi]

Listen to micks guide, this is the correct diagnostic procedure for diagnosing a abs wheel speed sensor fault.