ABS Issues

[Z51JEFF]

The ground for the ABS is on the driver side B pillar I believe.When I had an ABS issue on my 91 a few years ago I managed to collect several of the relays and an extra accelerometer and I also have the ABS cartridge for a Tech-1 scanner,you can borrow anything I have providing you pay shipping and I get it back.The issue I had was when I disconnected all of the plugs in the area of the CDM controller I managed to push the connector for the ABS out of the plug housing,killing power to the system.

[batchman]

Even shiny contacts can have issues. This car has spent a lot of time sitting.

I'm a big fan of DeOxit. While the content is available in several forms, this kit has lasted me years:

http://store.caig.com/s.nl/it.A/id.2...2&category=821

Good luck,
- Jeff

[zig]

Originally Posted by Z51JEFF

The ground for the ABS is on the driver side B pillar I believe.When I had an ABS issue on my 91 a few years ago I managed to collect several of the relays and an extra accelerometer and I also have the ABS cartridge for a Tech-1 scanner,you can borrow anything I have providing you pay shipping and I get it back.The issue I had was when I disconnected all of the plugs in the area of the CDM controller I managed to push the connector for the ABS out of the plug housing,killing power to the system.

Appreciate the offer. I found a Tech 1A locallay so picked it up for a pretty reasonable cost. Since I have three cars I can use it on I figured it would be a good investment. It came from a Cadillac dealer so it didn't have the Bosch adapter but did have the Mass Storage Cart. Got a Bosch adapter off fleabay so it should be here sometime this week. Other than a broken power cord that I had to fix, it works great. Had it on the 96 Vette and the 91 and works great.

Plan is to pull the plenum again this week and clean the ground point. I'm kicking myself now for not doing it when I had the plenum off the first time. Oh well. I have a slow leak in the vacuum solenoid and finally found one that holds so needed to pull the plenum to replace it anyhow.

[zig]

Originally Posted by batchman

Even shiny contacts can have issues. This car has spent a lot of time sitting.

I'm a big fan of DeOxit. While the content is available in several forms, this kit has lasted me years:

http://store.caig.com/s.nl/it.A/id.2...2&category=821

Good luck,
- Jeff

Jeff, True. It has definitely been sitting. Only 5,000 miles in 20 years. Will definitlye try the product you recommended. I have a hundred uses for something like that.

[zig]

Ok. ABS is fixed. Tore apart the plenum to get to the ground. Much easier this time but trashed the gaskets so had to wait for them to get the top end back together. While I waited, I pulled the halo and checked grounds on both driver and passenger side. Both looked new as did the one on top of the bell housing. Checked all the sensors again because I had the time. Check all the ground for the ABS and Ride Control because I was there. Everything was as it should have been. Less than 1 ohm resistance for all ground circuits.

Once the motor was back together I had also received the Tech 1A ABS adapter. Hooked it up and ran the ABS auto test and it passed. Cleared the 32 and 36 codes I had from before and ran it in monitor mode. Right Front had no speed signal. I know the sensor is good because I tested it. So I run it again to show the wife. After the power cycle now both the front sesnors show no speed. Too many wierd symptoms so I replaced the ABS computer with one I bought last weekend that also arrived while I was waiting for gaskets and bam. Passed auto test, no ABS lights, speed signals were all there and the best test I could think of passed - slammed on the brakes and the ABS Active light was bright and pretty and the ABS actually worked.


Figure I still saved money after getting all the tools, spares and Tech1A over taking it in for repair. And I like new tools.

[scottfab]

If you send me the failed unit I can try to find the root failure.
Part of my career was in root cause analysis of electronic component failure.

[zig]

Scott - I appreciate the offer and I think I'll take you up on it. I didn't have to perform root cause analysis of components but after 20 years in the Navy as a Fire Controlman isolating failures of computer, radar and electro-mechanical systems I did and still do a lot of fault isolation on just about anything that's broken. Unfortuately I have no schematics or diagrams to go off of. I'll pop it open to see if I can find anything obvious but if not I'll let you know.

[scottfab]

make sure before you open up the box that you know which lines are coming from the sensors on the front and focus your attention on those. Look for cold solder joints. also check for pins that may have broken or vibrated loose.

Originally Posted by zig

Scott - I appreciate the offer and I think I'll take you up on it. I didn't have to perform root cause analysis of components but after 20 years in the Navy as a Fire Controlman isolating failures of computer, radar and electro-mechanical systems I did and still do a lot of fault isolation on just about anything that's broken. Unfortuately I have no schematics or diagrams to go off of. I'll pop it open to see if I can find anything obvious but if not I'll let you know.