Hi,

In the last 5 times I have taken my car out, 3 times both the ABS and diff warning lights have come on. When i have stopped at a junction and turned the car off and re-started it they have not come back on.

Has anyone got any ideas as to what might be causing this? I'm guessing its not a big issue as i'm assuming they would stay on if it was.

Cheers
Simon

 

Frequently connected to low brake fuid, my car is incredibly sensitive and has to be absolutely full to avoid triggering warning lights

A possibility at least

 

Thanks for suggestion, i'll take a look.

cheers
Simon

 

Usually when a warning light illuminates it's indicating a malfunction with the system involved. Does the ABS / Diff lock function?

You know what happens when one assumes!

 

Fluid levels
Voltage/earthing issues (worse because of the rain)
Worn out bomb
Defective pressure switch
Weak pressure pump

Are all possible candidates.

I get someting similar from time to time and have done on and off for the last three years, like you say turning the engine off and on sorts it when it doesnt clear itself, usually just clears when you pull away. You could get someone to hook it up to a hammer but i'd guess it wont show any errors. The more serious failure, which wont give any warning lights, is dodgy ABS which can find unusual and scary ways to fail.

 

Probably not a worn out bomb - I had this replaced when I owned the car. Although come to think of it, it was when I had ABS problems when I first bought the car, so I suppose that was about 9 or 10 years ago. But, if it was the accumulator, I don't think it would clear with ignition off / on.

As I said to you today - my guess is electrical, because I did have those lights come on sometimes if I used the horn and I never did find the cause. I suspect that whatever it was has now got slightly worse.

Either that, or the previous owner sold you a dud.

ETA : By the way - I have Durametric, which I've already used with that car. It gives a LOT less info than it does for my turbo, but if you want to check for codes etc. let me know.

 

That would be interesting........

I'll be having a word with him :-D

Cheers
Simon

 

just corrected mine on a 91 C-2 by reconnecting wires that had been cut long before i bought the car. until i can get hold of the new connector i just electric taped the cut together and thats been over a week ago. have driven in rain and back and forth to the plant several times and no issues so far. found it while i was changing out the steering rack...lucky find.

 

what is this bomb you all are mentioning? do you mean pump?

i get abs warning light on and off. cleaned all the ground cables and the fluid is high. what are the likely culprit? when the abs light goes off, the voltage jumps.

 

It's the round bomb looking thing, which is the accumulator.

The abs systems needs a good clear power signal if you have a weak alt it can make the light come on. Sounds like a short, bad connection, alternator issue.

 

I recently got that symptom + no speedometer because a fuse was knocked loose in the fuse box.

 

ok....so this is one of those topics that has been beaten to death. There are simply too many reasons this could happen. It has happened to me twice with completely different faults. One was a defective airbag sensor. The second was a fault in the accelerometers. Both were readily addressed.
The only way I was able to get this fixed was to take the car to the wrench and get the fault codes read and cleared.
Save yourself the stress....go get it diagnosed.

just my $.02
jt

 

The good news is, we can rule out airbags - it doesn't have them.

Accelerometer is possible but unlikely - I had that problem when I bought the car - in fact, I think I was one of the first 964 owners to discover that the accelerometers can have a very unpleasant effect on braking (I got no warning lights, but the system would simply enable ABS too early and then decide you were skidding and simply release the brakes. I genuinely went through a red light once as a result). I therefore cleaned the accelerometer out every couple of years just in case - and I know for sure it wasn't the cause when I had these lights come on due to using the horn.

I think the good power signal / good earth is the place to start investigation. Note that it shouldn't be an alternator problem - it had a new alternator a couple of months before you bought the car.

 

I'm going to start looking at the earths etc soon. Having said that, it hasn't done it again for a while. I'll have a chat with you off thread soon as i need to pick up those tyres.

Simon

 

my ABS light issue was fixed. there is another thread here on abs light. i unplugged the harness from the abs computer, using a multimeter, there were easy instructions on how to test certain pins on the harness to pin point if there is a bad speed sensor on wiring. it turned out that my harness and abs computer had a poor connection. after spraying some electrical connection cleaner, the abs no longer pops up intermittently.

if anyone has abs light issue, i would recommend looking at the other thread on this forum.