Z51JEFF

The ABS is dead in my 91 and NOBODY has a clue as to what it might be.With as my of these cars there are out there I know Im not the only one that has had the ABS die.The system is the same from 86-91 I believe.I want to hear about all the problems people have had.I can fix it if I find the problem.Im not going to go through all the stuff Ive done but I will say it wont pull any TCs and wont communicate with any scanner Ive used,all I get is SERVICE ABS on the panel.Let hear what ya got.

walter schweigert

Z51JEFF

Dont anybody tell me to call Gordon Killebrew.Did that and it cost me $40.Guess what,still got no ABS.

Ricky 91 vette

welcome to the club!! i have the service abs on the panel since i bought my 91 2 years ago! it comes on and off, when its off my abs works great i took the car to the dealer when i first bought it, they charged me $100 to reset it and they told me it shows only bad conection 66 egnaution cycles ago and it should be fine now! but till today i have the same problem, and i gave up on it long time ago

Z51JEFF

How do you reset it,disconnect the battery?At first it would act up,fine one day next day dead then finally,poof its dead.Ive tried everything,different controllers,different relays,different accelerometers.

Steve59

On my 87 the light comes and goes. The previous owner said it was the pump, but it also could be dirt on the sensors, since it's an intermittent problem. Never had it looked at or fixed.

RS69

My 87 vette's ABS light came on yesterday, and I disconnected the battery and it still came back on. I would like to fix this issue.

samsonb

It will probably be expensive if you have to replace the ABS unit.

Aardwolf

Have you followed the FSM troubleshooting charts? There are things like tipping the accelerometer on it's side to make sure it works, etc etc. I removed the ABS system from my track car, the parts aren't terribly expensive.

jfb

Good dealers have a tester for determining what needs repairing on ABS units. A time ago my 87 had a bad rear star wheel pickup (mechanic mangled it pretty good). Recently my 87's ABS started coming on just starting from a stop and coming to a stop. The tester said it was the lateral acceleration switch which I verified with an ohmeter check with it level (its supposed to be zero ohms). I recommend you find a repair place with your year ABS tester.

Z51JEFF

I wont let anybody work on this car,thats the biggest obstacle as far as finding the problem.Ive had 3 accelerometers in the car,no dice.

Ricky 91 vette

No because the code will be stored so desconecting the battery wouldn't do any thing

toptechx6

From my 93 FSM, I can't swear it is the same for a 91.

The CCM on board diagnostics can be used to clear ABS/ASR system DTC's. Follow the procedure below.
1. Ignition OFF
2. Connect jumper from DLC terminal A to terminal G.
3. Ignition ON
4. Press Trip Reset button on DIC repeatedly to display 9.0 in trip monitor area of the instrument cluster.
5. Press Trip ODO twice to change the display to 9.7
6. Hold ENG/MET until "---" appears in the the speedometer area of the cluster.
7. Ignition OFF
8. Remove jumper from DLC

Here is a link to some good ABS information, courtesy of Hib Halverson

http://www.corvetteactioncenter.com/...abs/index.html

jfb

But you could just pay for the diagnosis and do your own repair. Without the diagnosis you have no means to find the fault. The first time my ABS malfunctioned I put the car on jackstands and used my oscilloscope to look at the waveform of each wheel sensor while I spun them and could'nt see any difference on any wheel, but later a tester found a defective wheel sensor.

c4cruiser

Don't think the early ABS cars had the same diagnostic procedures. A GM Tech I with the brake module can be used to display ABS related codes but the paper clip method works too but only for the 92 and later cars.

I know that my 87 ABS system can't be diagnosed with a scan tool. That system does not communicate with the ECM so a specific ABS tester must be used.

Have you tried cleaning the wheel speed sensors? Are the connectors tight and have no corrosion or dirt that could result in a bad contact? Are the sensors at the correct wheel? They are left and right specific.

Try pulling both front hubs to see if the reluctor rings are where they belong or have no broken teeth.

It's also possible that the ABS controller is having intermittent issues. Are the wire harness connectors at the controller tight? The ABS unit has three relays, a pump motor relay, a solenoid relay, and a module relay; maybe one is going south. Also check the ground connectors to make sure nothing is loose or corroded.

Z51JEFF

There are actually 4 relays in the ABS well,if a wheel sensor was faulty I should at least get a stored fault.Ive got some spare relays Im going to try out.Ive got voltage at the pump and ground from the 10 gage black wire.There is a ground at the leftside B piller that is the only thing I havent checked.

Z51JEFF

Nobody is wiling to do this and to be honest,I cant blame them.They have cars waiting for service the last thing they want is to work with some neurotic Corvette owner.

Z51JEFF

Anybody else?

jfb

Fix your OCD first.

ddahlgren

Find a shop that will let you watch what they do or buy your own Tech 1 for about 1800 if you can find one. I have never heard my ABS self test the light blinks and that is it and it has never gone off no matter how hard I try. If the ABS needs bleeding it is going to be messy and hard to avoid send a letter to GM about the poor design like they actually care.