ABS Service light?
 

1990 ZR1 - reading about many possibilities. Where should I start ? Waiting on my factory service manual CD to deliver.

Re: ABS Service light?
 

May be start with pulling code?

Re: ABS Service light?
 

I worked on a buddy's 93 (had been sitting many years) after I got it running had an ABS code was able to clear it with my scanner never came back. unfortunately I don't remember what code it was.

Re: ABS Service light?
 

You will need a GM Tech1A scan tool to diagnose and after fixing the problem, to reset the code.
If the problem turns out to be a faulty relay in the ABS system, I've dealt with this in the past.
The relay is made of pure unobtanium new, you will either have to source a used one off another 1990, or perform a mod like i describe in a post long ago.
Do a search for pasts posts by me on ABS relay mod.

Crabs

Re: ABS Service light?
 

Check the fluid level in the brake master cylinder first. Then get a ALDL code reader after that.

Re: ABS Service light?
 

Hi guys...
i always have the front reservoir with the oil level lower than the back reservoir....i have no leak...it's normal??
Also if i refill the front one after few miles the level goes down...i dont' know why...the car brakes well...

Re: ABS Service light?
 

Years ago I was having problems with my ABS and I went to a Corvette wrecking yard and snagged every relay I could get,got a bag of these things. OP, the sensors are magnetic and over time pick up debris from the road and need to be cleaned from time to time.

Re: ABS Service light?
 

Z51JEFF, if it is the wheel speed sensors picking up debris have you ever known of someone who has removed cleaned and replaced them and they still worked ?I would be very interested in how they were removed without damage. Thanks.

Re: ABS Service light?
 

Update to my original question / issue. Service guy said the relays are causing the ABS light to come on and someone installed aftermarket Bosch brand before me owning the car. He said only way to make light go off is to have GM relays which cannot be bought new. So what next before I yank the bulb to make this problem go away ? Or will yanking the bulb cause another issue ?

Re: ABS Service light?
 

how much and are you sure they are good ?

Re: ABS Service light?
 

I would be interested to know how your "service guy" came to that conclusion. What were the codes and what tests were performed?

Re: ABS Service light?
 

I did not ask enough questions which is on me. I think he just read on line that can be the problem that causes this and saw the aftermarket relay installed. He was adamant about wanting no part of further service work relative to electrical issues on this car because he knows of the electrical nightmares that can happen - again I guess he read about that as well. So $300 dollars for his analysis professional opinion only. So I am now contemplating finding the the relays needed to replace them again and hope for the best.

Re: ABS Service light?
 

Is this the thread/post?:


http://www.zr1.net/forum/showthread.php?t=31034

Re: ABS Service light?
 

Happen to be troubleshooting my ABS as well as it is currently non-functional.


My initial steps (low hanging fruit) will be as follows:


1. Pull codes (jumper A-H pins in ALDL connector),
2. Inspect ABS unit and wiring in the well behind the driver's seat,
3. Check ABS associated fuses (none blown, correct size, seat tightly),
4. Check grounding wire (loose, corroded?),
5. Attempt to reseat relays/connectors by removing/disconnecting then re-installing/reconnecting,
6. Inspect ABS sensors/wiring for damage.


If the above do not fix, I'll need a new TS plan. I managed to find the Bosch ABS training manual on eBay so will be reading through the Service Manual supplement and the trng man to get more familiar with the system and devise a step-by-step plan. If I had a set of relays I'd probably just try those right off the bat (more low hanging fruit), but I don't at the moment.

Re: ABS Service light?
 

OP,I would venture to say it's time to look for another -guy- I've got a bag of relays I'd loan you if it would help. Now these came out of wrecked cars so I have no idea if they work or not. Not sure why you can't buy these used from any Corvette wrecking yard.

Re: ABS Service light?
 

Yes, that's it.

Beg, borrow or steal a Tech1A scan tool with the appropriate ABS module.
It is the ONLY way to properly diagnose and reset the ABS code.
Trust me on this.

Good luck.

Crabs

Re: ABS Service light?
 

Thanks!