squarehead

My warning lights for ABS, Traction Control System and Air Bag all came on a couple weeks ago, they have not turned off and I have had no luck sorting the failure. I have had the TCS and ABS lights occasionally do this in the past couple years, in the cold weather while backing out of the garage the warning lamps come on and stay on till I next start the car and then they would go out. Never did the Air Bag lamp turn on.

I am most concerned with the ABS and TCS not working and they are in fact not working (not just a false light). I searched Z28.com and found only a couple threads with similar failures. One said check the third brake light; which I did and found not working; I replaced the bulbs and it now works but still the ABS and TCS fail.

One thread advised double checking the wheel sensor wire connectors which I have done, cleaned and added di-electric grease before reattaching them. Still nothing.

I found a thread that suggested to have the dealer check the systems with their more advanced diagnostic tools which I tried to do yesterday at my local dealer Victory Chevrolet. The dealers tech could not communicate with the modules that control the ABS and the TCS. He called GM tech support and they told him that his only next move was to replace the modules until they could be contacted by his diagnostic reader. The modules are very expensive or not available so I paid him for his time and I have the car back but still not right. He was able to get the warning lights to turn off once (does not know how) but then they came back on during a test ride.

Does any one have any experience with a failure of this sort that could give me a new direction for my repair efforts? Thanks in advance!

GaryDoug

See this topic: https://www.camaroz28.com/forums/com...95-lt1-874306/

It is for free pc software that you can download using a link in the topic. I wrote the software. It requires a pc that can be placed near or in the car and an OBD1/ALDL cable ($55 at Red Devil River, order the 16-pin one). It can show you all the trouble codes and some live data (like wheel speeds) for the engine, ABS, and SIR (airbags) modules. It can also clear the trouble codes for all 3 modules, turning off the trouble lamps. I wrote this specifically to mimic the capabilities of the expensive Tech 2 handheld scan tool formerly used by the GM dealerships.

Depending on the particular fault, some of the modules can be inexpensive. I bought a used ABS control module for $20.

shoebox

Try checking/cleaning and tightening the ground on the RH shock tower.

squarehead

Garydoug and Shoebox, thanks so much for your replys! I will start with shoebox's suggestion as it is quicker to implement and report back when it is done. If negative result I'll down load the software and give it a go. Thanks again.

squarehead

Shoebox it worked! (Wayne and Garth look at each other then bow down wailing "We're not worthy. We"re not worthy!)

The ground stud had worked slightly loose from the body but was still tightly attached to the big ground cable from the battery. I removed the 10mm nut from the stud, removed the ground cable copper ring terminal, then removed the stud from the body and two solder dipped ring terminals that were under the stud were also free.

I wire brushed the stud and all the ring terminations. Scraped and wire brushed the body at the stud mount hole. Then dielectric greased the stud where it penetrates the body and the body hole and reinstalled the stud to the body. I then greased all three shiny clean ring terminals and fastened them under the 10mm nut and voila all three lights: TCS, ABS and Air Bag turned off after the proper start up sequence.

I ran the car up to 10 mph on my gravel drive way and nailed the brakes and the ABS worked perfectly.

Big thanks to Shoebox, Garydoug and Z/28.com for helping me fix this!

shoebox

Great news and an easy fix for something that seemed so daunting and expensive. That ground is pretty important.

GaryDoug

Congratulations. I guess the lesson here is to follow Occam's razor Principle: Follow the simplest explanation whenever possible.

squarehead

Garydoug, I did go ahead and order the 16 pin connector and download your diagnostic program; I want to be better prepared for the next problem! Also reading up on the software link it sounds pretty cool and fun if I can get it sorted. I'll let you know!

Gentlemen, thanks again!

Keith