abs/braking problems

R

R0B

Member
ok, went out for a short drive on saturday and just as i was pulling back onto the estate i felt a judder through the brake pedal when i applied the brakes at low speed (20ish mph). took the car out the next day but this time there was no judder in the pedal but the abs, traction and (!) lights and were displaying. the braking power still appeared to be normal.

took the car out again today and the pedal was juddering really bad when applied, then the lights come on and the brake pedal is normal again. so im thinking that the abs is trying to activate every time the pedal is pressed for some reason but when the computer realises there is a fault it deactivates the system and ive basically got a non abs braking system. tbh, ive been thinking about buying a vagcom unit for some time but i think this has now swayed me but before i do, does anyone have any ideas or has had any similar experiences?

car in question is a 2001 1.4se petrol with 52000 on the clock. now this may be important, the drivers side front wheel bearing was changed 2 weeks before this happened, ive done about 200 miles since then. is this connected or just a coincidence?
 
Mine suffer similar problem but judder through the brake pedal are not so often. On the VAG scan there was faulty rear wheel ABS sensor. I have changed it but it does not help. Now I am looking for other solution of this problem.
 
R0B said:
ok, went out for a short drive on saturday and just as i was pulling back onto the estate i felt a judder through the brake pedal when i applied the brakes at low speed (20ish mph). took the car out the next day but this time there was no judder in the pedal but the abs, traction and (!) lights and were displaying. the braking power still appeared to be normal.

took the car out again today and the pedal was juddering really bad when applied, then the lights come on and the brake pedal is normal again. so im thinking that the abs is trying to activate every time the pedal is pressed for some reason but when the computer realises there is a fault it deactivates the system and ive basically got a non abs braking system. tbh, ive been thinking about buying a vagcom unit for some time but i think this has now swayed me but before i do, does anyone have any ideas or has had any similar experiences?

car in question is a 2001 1.4se petrol with 52000 on the clock. now this may be important, the drivers side front wheel bearing was changed 2 weeks before this happened, ive done about 200 miles since then. is this connected or just a coincidence?
Click to expand...

I had similar with an ABS failure caused by the bearing.There is an ABS pick up ring within the hub that could have been damaged when changing the bearing a scan will confirm or deny this.Don't know if you changed the complete hub or just the bearing.You can check the wiring harness behind the wheel for anything obvious as well
 
thanks for the replies, i expect it to be the sensor on the same wheel that the bearing was changed on. just need to buy vag com now, anyone know the best place to buy a genuine cable from?
 
I don't, but I bought one of the 10 quid cables of eBay which I use with the shareware VAG-COM, and it serves me fine - I couldn't justify the cost of the 'full monty'.

P
 
Update. Now armed with my vag com cable it has identified fault code 00285 "mechanical malfunction" on the right front. i used the measuring blocks tool and the sensor on that wheel was not registering the speed while the other 3 all registered the same speed. can anyone tell me how to remove the sensor and what i should use to clean it? if that does not fix the problem then i will replace the sensor and see how it goes.
 
Ideally, you'll need to remove the wheel, caliper and disc, plus the splach shield from the corner in question, then undo the single 5mm (think!) allen head bolt and wiggle, firmly but gently (!) to get the sensor out.

What you'll see is a rectangular, flat ended piece, that pokes into the hub housing around 20mm. The end should be flat and fairly clean, with no signs of wear on it.

I've recently seen a sensor that was damaged after the bearing wasn't inserted fully, so check this out for being a possibility - the bearing was replaced by a franchised VW dealership too apparently!

Cheers

Mike
 
Zorka5 said:
Mine suffer similar problem but judder through the brake pedal are not so often. On the VAG scan there was faulty rear wheel ABS sensor. I have changed it but it does not help. Now I am looking for other solution of this problem.
Click to expand...


I found the solution so simple that It was hard to belive. I tightened this huge connector near brake pump with ABS module and It solved the problem. I wondering how to disconnect it to check carefully all pins if there are ok.

Before this I had changed ABS sensor and wheel hub - Audi ASO advise :mad:
 
Last edited:
R0B said:
thanks mike, how will i be able to tell if the bearing wasnt inserted fully?
Click to expand...

It'll show as an uneven wearing of the pads (outer pad worn, inner one hardly touched) and also, you'll see that the hub flange (where the wheel bolts attach) is sticking out too far - you should not be able to fit even the smallest of fingers in between it and the hub housing.

Cheers,

Mike
 
I would be glad to hear the outcome of the sensor as I had a similar experience (all the lights on the dash, ASB/traction and red brake warning light appeared on my car last week four times!)
The breaking did not appear to be affected and when I switched the engine off and back on the fault cleared.
Mike:confused:
 
ive still got to get round to sorting this, the last few weekends the weather has been lousy but ill let you know when its done. im thinking that the sensor may not have been put back in correctly after the bearing change so after a couple of weeks driving round it has moved a bit and now it cant get a reading.
 
update: had the sensor changed today but still the problem persists! the mechanic pointed out that the pads on the driver's side are not seated in the caliper as they are on the passenger's (about 5mm out). he mentioned something about the caliper bolts being cross threaded which is causing the sensor to be too far away from the hub so it cannot get an speed reading. should be getting the bolts replaced on tuesday so hopefully this will be the end of this problem.
 
Zorka5 said:
I found the solution so simple that It was hard to belive. I tightened this huge connector near brake pump with ABS module and It solved the problem. I wondering how to disconnect it to check carefully all pins if there are ok.

Before this I had changed ABS sensor and wheel hub - Audi ASO advise :mad:
Click to expand...

Solution was not so simple as I thought. Problem was random and did not appear correctly on VAG scan that is why quite hard to track.

One of the ABS wheel sensor (not this one that I had changed) housing was broken and it caused short circuit when it was wet. This have damaged the wheel sensor circuit in ABS steering module (question why it was not "short circuit resistant", it could be with additional small resistor:mad:). So the ABS steering module was repaired, few resistors were added to avoid such case in the future, steering module software was reloaded, broken wheel sensor was changed and never seen (!) sign again. All this cost a fortune :mad:

Sad story, but do not be afraid the guy who did all this job said this kind of fault is quite rare.
 
Last edited:
I've just had the dreaded Tracking Control light, ABS light, and the ( ! ) error appear within the last few days.

Was on here all evening yesterday to try and find out the possible problems. How much would a new sensor cost roughly? It possible the cold could contribute to the error?

Also anyone know how much a diagnostic test would cost from the stealers? Do the stealers run the test during the full service, as recently had this done with no major issues! Really need to get this sorted as, neither tracking control or ABS are working at the moment, and I was skidding all over the place in the snow on the way home from work! :(
 
Last edited:
Speed sensors are around £45 each, but you're better off getting a scan done to pinpoint the problem.

Audi normally charge an hours labour for this (bank on around £100-120) and members such as myself who have full diagnostic capabilities normally charge in the region of £20.

Just because there were no faults recently on the service doesn't mean that they missed something - it's possibly that this has happened recently.

Cheers,

Mike
 
Thanks for the info Mike. Where is the best place to get parts - direct from the stealers?

Also, where abouts are the ABS wheel sensors? are they easy to get to, just so i can see if there is any damage to the housing.

Knocked the front of my car (quite hard) a few weeks back on the curb, wondering if I damaged one. On most of the threads i read yesterday it was pretty conclusive that the only way forward is to have a scan...it may be time to invest in vag com.,,:confused:
 
For speed sensors, the dealers are the only place to buy from.

The wheel speed senders are located in the top of each hub housing, just behind the splash shield behind the brake discs, so the'yre pretty well protected.

A knock may have had an effect, but a scan is the most effective way forward.

Cheers,

Mike
 
Skipton01 said:
For speed sensors, the dealers are the only place to buy from.

The wheel speed senders are located in the top of each hub housing, just behind the splash shield behind the brake discs, so the'yre pretty well protected.

A knock may have had an effect, but a scan is the most effective way forward.

Cheers,

Mike
Click to expand...

Sorry for all the questions...where did you get your vagcom from? on their site its about £290+VAT, does that sound about right? Are they any other places you can source genuine vagcom from (i.e. not ebay)
 
You must log in or register to reply here.
Back
Top