My ABS light just came on yesterday
95 4dr 2x4.
The brakes seem to be working
ok. What can I troubleshoot?

 

My ABS light used to come on a lot and eventually would cause my brakes to lock up and not release. What happened was the motor inside my ABS unit blew. What I did was disconnect the ABS unit and all the ABS censors and I haven't had any braking problems since then. This probably isn't the safest method but like I said, I've had no problems since then. I wouldn't do this though unless you start to have the same problems I was having.

 

ABS light can mean several things. The first thing you need to do is find someone who can scan he code.

More then likley its just a dirty sensor, and that could be due to a failing hub assemble. Or it could be due to different sized tires. Are they all at proper psi? You do have 4 tires of the same size right?

The ABS light means the ABS system ahs detected a fualt, and it turned off the ABS system. Your brakes will still work, however when you slam your foot to the floor for a sudden stop the ABS system won't kick on. You will have to manually pump the brakes to slow down faster. Locking up the tires mkaes you skid, and you wont have control of your truck while in a skid, plus it takes longer to stop tehn if the tires were turning. ABS simply stopps your brakes from locking up so you stop faster and have control. It pumps the brakes for you, thats why you feel the pulsation.

 

Autozone said that a code can be read only
if the check engine is set. Is there other codes
generated?

Tires were just pumped with air before going out after a few weeks.
I think the tires are stock size and all the same.

I will check out the abs unit tomorrow.

 

I just noiticed you got a '95. '95 is kind of a bastard year. '94 is OBDI, and '96 is OBDII. '95 is like half way between the two. Contact Swart, he knows more about those theings then I ever will.

 

I tried dissconnecting the red power lead to
the ABS and the abs light went off and emergency
lite came on.
I reconnected it and drove on gravel. stepped on brakes
and wheels locked up.
So I guess the abs is no longer working.

Any thing I can troubleshoot?

 

The ABS system uses a special scanner, not the same one used to check engine codes.
You need to know the fualt code. Without that code you can send a ton of money on new parts that you may or may not need. Contact Swart, member on this site, look in the right hand column and you should be able to see his name. Click on it.

 

I'm not sure what is required for testing the ABS on a '95... I do not believe that the communication system for the ABS controller was moved to true OBD2 until '96 and even then it was quirky. I'll have to look through my references and see what I can find on that subject when I get some time.

 

The Kelsey-Hayes RWAL EBC4 ABSwas used from 1988 through 1995 on 2 door S10 Blazers and light trucks (The 1995 T/S-Series Trucks and Blazers have1st generation ABS). The Kelsey-Hayes 4WALEBC4 ABS was introduced in 1991 on 4-door S10 Blazersand used through 1995. The main problem with thes ABS brakesis the EHCU(Electro-Hydraulic Control Unit) ABS pump relay. Unfortunately that relayis located inside the EHCUand isnot serviceable. The relay usually malfunctionswithin 80,000 miles and the ABS pump on the EHCU ceases to run. When the pump fails to run, the RWALdump valve in the EHCU will stick open and the brake pedalwill be soft and oftenfall to the floor with disasterous results.The symptoms areexactly as ifthere is air in the system or the master cylinder is by-passing. Many master cylinders have been replaced and systems bled multiple times because of this problem and it does no good. No Tech-1 ABS faultcodes will be set because the diagonstics cannot tell if the dump valve is open or closed. The ABS light on the instrument panel will come onand go out in two seconds as normal but if the ABS pumpis malfunctioning because the realy is at fault, you will not hear the ABS pump running when you apply the brakes.

The only solution to the problem is to replace the EHCU with a rebuilt unit (new ones are not available) and bleed the system. Installing a used EHCU is a crap shoot because they probably have the same problems or soon will.The front disc brakes have been doing 100%of the stopping on my 1991 S10 Blazerbecause therear drum brakes quit working when the ABS pump relay failed about ten years ago.I must replacetheEHCU with a rebuilt unit at a cost of $1007.00 less $313.00 for my old one. Rebuilt AC Delco EHCU are availablefrom GM for $1440.00($800.00 with a dealer discount). The ones you see on e-bay for $800.00 are those units.

The devil designedChevrolet Blazers and that iswhy they are called"Blazers."