ABS light.

[Heat Seeking Missile]

I've noticed a couple of times in the past few days that my ABS light comes on when I start the car, but doesn't go off. If I switch the ignition off and try it again, it comes on and goes off again as it should.

I haven't tried drving the car with the light on, I didn't think it was too good an idea.

Anyone know what it might be? Electrical glitch perhaps, or something more serious?

Mark

[sheppardnias]

Not sure it's exactly the same but my ABS light was coming on when I started the car I just don't remember if it stayed on. I think it did though. My fault was due to low voltage while cranking. The ABS ECU was throwing up an error code on occassion, especially if I left the car for more than 48 hours.

Since I fixed the power leaks and have kept the battery charged, I haven't seen it.

Mine was noticeable when the voltage dropped below 10V (IIRC) while cranking.

[spink]

could be any number of things,best to check it with vagcom.Had a couple of problems myself lately.First off i was getting a code saying that one of the rear sensors was knackered,actually turned out that the pickup ring on the cv joint had disintegrated.And then last week had the abs light flashing everytime boost was coming on,the diff switch light was also lighting up.This one turned out to be the diff controller under the rear seat.Didnt throw a code for that one though,just happened to hear a strange sound coming from under the seat one day.

[Error404]

Not sure it's exactly the same but my ABS light was coming on when I started the car I just don't remember if it stayed on. I think it did though. My fault was due to low voltage while cranking. The ABS ECU was throwing up an error code on occassion, especially if I left the car for more than 48 hours.

Since I fixed the power leaks and have kept the battery charged, I haven't seen it.

Mine was noticeable when the voltage dropped below 10V (IIRC) while cranking.

i second that - check your alternator and / or alternator belt.
when voltage is low it seems to cause problems with the ABS.

[Heat Seeking Missile]

Oh right, thats an unusual symptom. I'll take a look at that. It has been coming on before cranking and staying on though but I never thought to look at the Volt gauge. Cheers

Mark

[S2central.net]

Yeah the ABS will throw up a leg if it thinks voltage or earth is out of whack... Worth checking all contacts in round the relays at the ABS modulator and check the resistance across all the ABS sensors - just a 2pin plug at each corner. If you have dicky contacts they will throw up problems - cant remember if those get logged sitting stationary though or if you need to be above a certain speed before the ABS logic says 'eh up' !

[Error404]

pretty sure its speed sensitive as I have no rear sensors in my CQ at the moment and if i forget to press the cancellation switch it doesn't register a fault until about 40mph.

[Heat Seeking Missile]

I've been away for a week and the past day or so since I came back, it wouldn't go off at all. I did a run of about 35 miles today and it has been ok since. It certainly sounds like low voltage, as the battery will have been down after 7 days of standing. Is it still worth checking something on VAGCOM or just put it down to a very slow drain on the battery? Which could be anywhere!

Mark