ABS Light, possible problems?

[p0l1wrath 10]

ABS light came on whilst using brakes (and ABS) during the snow!

Knowing the car would fail anyway, i put the car in for MOT today to see if anything could spread some light to what it could be?

Rear brakes came up as an advisory wondered wether them being low could have anything to do with it?

If not what are the problems a solid ABS could mean?

Cheers

[buttles 0]

If you spin the front wheels for long and fast enough it will put the ABS light on. VCDS (Vag Com) will tell you what triggered it and reset it. What car? If a VR it might have annoyed the Traction Control by hammering the front brakes.

[p0l1wrath 10]

If you spin the front wheels for long and fast enough it will put the ABS light on. VCDS (Vag Com) will tell you what triggered it and reset it. What car? If a VR it might have annoyed the Traction Control by hammering the front brakes.

 

Oh ok,well I was deffinately spinning the wheels long and fast and sometimes I was hammering the front brakes as well! It's a 93 VR6 and plugged the vag com in yesterday which couldn't tell me anything about it and didnt turn it off with a fault code erase, obd1 by the way so don't know wether this means it won't tell me but couldn't hook up to the brake electrics, only engine

 

Cheers

[efil4sbuD 0]

Get yourself some electrical contact cleaner and spray it in the ABS pump plug first of all. Give it a good squirt in the plug and socket.

 

A couple of quid here might save you much more on ABS sensors and sensor rings - not to mention the time to do those jobs.

[p0l1wrath 10]

Ok cool ill give that a go, if that doesn't work what's usually first thing to check?

Cheers

[efil4sbuD 0]

Well, it's hard to say. I would expect VAG COM to give an error code for one of the four sensors if one was faulty but I think you said there was nothing.

It is supposed to do a self test when you start up with the light flickering slightly then going off. If it stays on, I assume that it's not completing the test and so I would suspect a dodgy electrical connection at the pump rather than a sensor which is what the contact cleaner should help to fix.

You could search on here for the ABS start up routine and see if anything being described sounds familiar.

[dr_mat 0]

Spinning the wheels won't put the ABS light on, that light ONLY ever comes on if there's an actual component failed (or, as said above, it's doing the ignition-on self test, after which it should always go out and stay out).

I don't think that the ABS gives a monkeys about the thickness of your brake pads, so I doubt that's related to it.

Edited February 15, 2013 by dr_mat

[VWVW 1]

You may have collected some magnetic dirt on the tip of the abs sensor. Maybe it just need a very gentle clean on the tip of the sensor if you can get to it ??

[buttles 0]

If you take your car onto a rolling road then it will put the abs light on. I don't know at what speed the abs ecu will detect an unacceptable difference in front to back wheel speed. A temporary spinup on snow shouldn't be enough though.

[dr_mat 0]

I've never seen that on my VR when it's on the rollers.. maybe that happened on earlier cars?

Usually only puts the light on if a sensor goes open circuit.

[p0l1wrath 10]

Ok guys cheers for the suggestions doing a bit of work on the car tomoro anyway, so well give me a good time to have a good look and a little fiddle :)

 

So with it being obd 1, am I able to look at anything other then engine electrics? The console has options for transmission and braking electrics but could establish a connection?

 

Can't see anything to do with abs startup routine, does anyone know anything about this?

 

Haven't actually mentioned this and suppose I should have, the abs doesn't work anymore, don't know of this obvious or not?

 

Cheers

[efil4sbuD 0]

 

Haven't actually mentioned this and suppose I should have, the abs doesn't work anymore, don't know of this obvious or not?

 

Cheers

 

I've had exactly this problem recently. The light stays on after starting up when it should go off. My ABS didn't work when the light stayed on either.

 

VAG COM once told me that I had a duff rear sensor. I changed it but after a couple of days the light was back on. I eventually sprayed the main electrical connection and the fault has gone and the light now goes off. I should have done this first and saved myself a whole load of grief trying to change the sensor.

 

During the start up test it must check each sensor and report back if it finds that the sensor appears damaged or non responsive. However, if the electrical connector isn't making contact then this is exactly what the test will find and report it as a duff sensor.

 

Start with that main connector on the ABS pump. It's easy to get to and the contact cleaner spray is cheap - get it at a parts store or Maplin, Servisol Aero Kleen 50 is what I use, it's excellent.

Replacing a sensor is certainly more work and a lot more money and it may not be at fault at all. Do the easy things first.

 

If you want to read about what happens during the start up routine I'm sure it's on this forum somewhere, you'll have to search for it.

[Hofmiester 10]

Hi Guys,

Just adding to this as my ABS light came on yesterday and it VCDS says that all 4 sensors have reported and "implausable signal" that fact that it is all four suggests something funky has gone on with the ABS connector.

 

I'm guessing it is the largish connector going to the bottom area of the ABS pump attached to the bulkhead? If so that I can't get the bugger off, there is a clip on the top that I can see but I'm wondering if there is another on the underside of the connector that I need to push in to release?

 

Cheers

 

Ron

[p0l1wrath 10]

Bringing this back to life for hope of some more answers, I've sprayed all the abs plugs I could find and changed all the sensors my light is still on! What's next on the list? Control unit or pump? Or is there something else it could be?

Cheers

[Hofmiester 10]

I found this problem today on mine, worth a check!

 

http://the-corrado.net/showthread.php?79622-Advice-needed-how-to-fix-broken-ABS-connector

[p0l1wrath 10]

Ok cheers pretty sure I had that cable off to spray contact spray on, and didnt notice any damage to it or any of the wires? Ill have another look tomoro when it's light, but if not does anyone know what's next on the list?

Cheers

[p0l1wrath 10]

Cable into pump is sweet! All connections look good! Pins and contacts onto abs module are all clean as well! Unsure of what to do next?

[buttles 0]

I would be looking at the ABS Relays and associated fuses found up just in front of the glove box. A swine to get to without removing the box but can be done. Real shame vag-com won't talk to the ecu. You mention that the ABS wasn't working anyway so I assume the light was already on while you were playing in the snow?

[p0l1wrath 10]

No, light come on whilst i was playing in the snow, had a look at the fuses and relays yesterday, all contacts look great no moisture up there, bought a new abs pump and going to fit that on sunday, hoping that the solinoid in mine has gone.

[Jonathan Claxton 10]

disconnect the battery over a night then reconnect in the morning, if theres no fault in the system that should turn the light off mate

[p0l1wrath 10]

ive tried disconnecting the battery, and by no fault in the system, do you mean a fault that vag come could read?

[Jonathan Claxton 10]

ive tried disconnecting the battery, and by no fault in the system, do you mean a fault that vag come could read?

 

No I mean a spike in the system not a fault, if you have tried the battery then there is Deffo a fault in the system, may be a dodgy sensor or a broken abs ring etc, needs investigating