ABS is dead

[Z51JEFF]

What would cause the ABS system to be inoperable?The fluid is full and there doesnt seem to be any problems with the brakes.For the past week the Service ABS System lite has been on so while out for a drive today I was able to get the brakes to lock up.I need to dig out the FSM but thought Id try this first for any clues.

[tomtom72]

Jeff, Is the fuse intact? That is my first thought, and next would be to use Gordon's jumpers to pull codes. I know on my snap-on scanner I need the software cartridge for the ABS to use the scanner to pull any codes on the ABS system. That's why I have a set of Gordon's jumpers, as they make it easy to ask the rest of the systems what's up.

...but, I have a 90 and I think the 91's & up are a different system...

:cheers:
Tom

[Z51JEFF]

All the fuses are good.I went down to the auto parts store and picked up one of those cheap code readers and when Im leaving the parking lot the Service ABS light goes out.Cruised around,stomped on the brakes a few times,activated the ABS system and everything seems to be working.Go figure, after a week with the light on,drag out the FSM,start asking around and spend some money it goes away.But isnt that the way these problems go?Ive still got a code so most likly the problem isnt gone,just have to get the code.

[GOLDCYLON]

Maybe a bad ABS wheel sensor. One out of the four could be throwing a code.

[Z51JEFF]

Maybe a bad ABS wheel sensor. One out of the four could be throwing a code.

Im hoping its this easy but wont really know until I get a code.

[Z51JEFF]

Well,Im still fighting this.One day its fine the next its dead.Ive taken the car to a Corvette shop to see if they could just pull the code,bought a scanner,used pro scanner and used the paper clip trick,no dice.It wont display a trouble code,I can get the 12 code but wont go past that.Is anybody in the CA Bay Area with a scanner that can help me pull the trouble code before I start pulling parts?I was told by the service tech at the Chevy dealer that the ABS system will not store a code but will only display a code when called for when the Service ABS light is on,any of this sound right?Ill figure it out sooner or later.

[GOLDCYLON]

Jeff your going to need to find some one local with a Tech1 or Tech1A scanner/programmer. I show 76 possible fault codes for the ABS system in my manual alone. It is a complex system from what im reading. GC

[Z51JEFF]

Jeff your going to need to find some one local with a Tech1 or Tech1A scanner/programmer. I show 76 possible fault codes for the ABS system in my manual alone. It is a complex system from what im reading. GC

Its the Tech1 scanner with an interface jobber.Ive not really looked at the sensors,is there a connection at the sensor and them a plug that goes into the harness?Ill trace down the problem,one things for sure,I dont find the problem it wont get fixed.Couple of places would only scan for codes if they fixed the car,not gonna happen.

[Jeffvette]

Just so you know, there are 5 codes which can only be read by a tech 1.

[lbszr]

Its the Tech1 scanner with an interface jobber.Ive not really looked at the sensors,is there a connection at the sensor and them a plug that goes into the harness?Ill trace down the problem,one things for sure,I dont find the problem it wont get fixed.Couple of places would only scan for codes if they fixed the car,not gonna happen.

Something easy to check, rear sensors get build up of metal particles on them, probably depends on what kind of brake pads you use. Excessively worn wheel bearings can cause it also. There is a plug and keep in mind the controller is probably static/elect sensitive and might not like multimeters. After the weekend let me know if you want a res. value for front ones, I have some out, I couldn't find a value in a book.

[GOLDCYLON]

Just so you know, there are 5 codes which can only be read by a tech 1.


And the Tech 1A reads the rest of the gambit?

[GOLDCYLON]

Its the Tech1 scanner with an interface jobber.Ive not really looked at the sensors,is there a connection at the sensor and them a plug that goes into the harness?Ill trace down the problem,one things for sure,I dont find the problem it wont get fixed.Couple of places would only scan for codes if they fixed the car,not gonna happen.

Yes it plugs into the ALDL port and has a scan capture mode by frame rate. Amongs solenoid tests, purging, Gear testing and each wheel for the correct speed inputs. And this is all from what im reading :jawdrop: its a very complex system and im thinking only the 1A can test ALL these parameters.

[Jeffvette]

And the Tech 1A reads the rest of the gambit?


There are 5 codes that can only be read by a tech 1 or tech 1a. So a paper clip or cheap scanner does no good.