SERV and ABS Light On Dash

[PaulyMcK]

Recently, in my 16v 04' Dynamique the SERV and ABS light come on. These warning lights do not come on as soon as I turn on the car - only when I'm going at around 50-70mph.

The car performs fine, and new brake pads were only fitted in January. However, sometimes when I'm braking at slow speeds (i.e. approaching a junction or roundabout) there is a noise when I brake - sounds like the brakes are slipping and not being effective - yet it only happens when breaking at slow speeds.

My MOT is due in the middle of November and I am looking for some tips if anyones has had something similar?


Cheers

 

[Beef-Mc]

Have a look at the ABS rings make sure there not broken or covered in muck for starts.

 

[5678]

First thing to do is check the brake pedal sensor. There are guides on here about how to remove and reset it.

TBH, for what they cost, I'd just put a new one in straight away.

Next thing to check will be ABS sensors.

 

[Martin.]

I had the same issue for weeks. Adjusted the brake pedal sensor a few times and it the lights still popped up. Replaced it for about 15 quid or whatever it cost and now all is fine..

 

[5678]

If it wasn't clear from my post, I had the same issue and a new switch fixed it.

 

[cookie92]

I had the exact same problem. And would kick in at low speeds and lights would go on at about 50 mph. Turned out to be my abs relucter ring. It's a ring of teeth on the wheel end of ur drive shaft. It will be cracked or missing teeth. You can a good one off eBay with a warranty for less than a tenner. Realy easy to replace and the problem will be fixed. Me and my mate sorted mine in less than hour and not had a problem since. Hope this helps.

 

[MicKPM]

If it wasn't clear from my post, I had the same issue and a new switch fixed it.

As per the OP's original post he said it happens at speeds of 50-60mph or greater so unlikely to be the brake pedal switch and more likely a faulty reluctor ring on the driveshaft.

If it was a pedal switch fault it would be declared or MIL "on" as soon as the system finishes its integrity check (5 secs after "key on") or when he touches the brake pedal. This is speed related and most likely a wheel speed sensor losing resolution (normally caused by a fracture to the ring structure itself).

The car performs fine, and new brake pads were only fitted in January. However, sometimes when I'm braking at slow speeds (i.e. approaching a junction or roundabout) there is a noise when I brake - sounds like the brakes are slipping and not being effective - yet it only happens when breaking at slow speeds.

My MOT is due in the middle of November and I am looking for some tips if anyones has had something similar?

The reluctor ring will be faulty chap and if you saw the signal in wave form the problem would be obvious. The reason why you're getting the noise is because the ABS system is seeing the faulty signal and is interpreting it as a "stall" and so tells the pump to start modulating (hence the noise).

Mick
Diamond Motors

 

[PaulyMcK]

Thank you everyone for their replies. Top Lads, will post in here when I have replaced the reluctor rings and let you all know.


Cheers

 

[Martin.]

Keep us updated

 

[Pulsator]

I had the same issue for weeks. Adjusted the brake pedal sensor a few times and it the lights still popped up. Replaced it for about 15 quid or whatever it cost and now all is fine..

Sorry to intervene on the thread, BUT................

Mine is also doing this, but all my ABS rings are intact - it is very on and off tho sometime mine will be on when start up the car other times it wont be :s and sometimes comes back on at any speed really but usually just goes back off ???

Does this sound like the brake pedal switch or possible ABS sensor needed ??

 

[daveypower]

As per the OP's original post he said it happens at speeds of 50-60mph or greater so unlikely to be the brake pedal switch and more likely a faulty reluctor ring on the driveshaft.

If it was a pedal switch fault it would be declared or MIL "on" as soon as the system finishes its integrity check (5 secs after "key on") or when he touches the brake pedal. This is speed related and most likely a wheel speed sensor losing resolution (normally caused by a fracture to the ring structure itself).



The reluctor ring will be faulty chap and if you saw the signal in wave form the problem would be obvious. The reason why you're getting the noise is because the ABS system is seeing the faulty signal and is interpreting it as a "stall" and so tells the pump to start modulating (hence the noise).

Mick
Diamond Motors

Serious knowledge.

 

[Martin.]

Sorry to intervene on the thread, BUT................

Mine is also doing this, but all my ABS rings are intact - it is very on and off tho sometime mine will be on when start up the car other times it wont be :s and sometimes comes back on at any speed really but usually just goes back off ???

Does this sound like the brake pedal switch or possible ABS sensor needed ??

Sounds exactly like the issue I had mate. I had the brake pedal switch replaced and the lights haven't popped up since.. yet!

If they do return I will take a look into what Mick has written about. But for now all seems good and there are no logged fault codes.