'95 850 Turbo / ABS Question

[scottyscott]

I've read alot on MVS about the ABS module faulting and needing to be replaced. My lights have started coming on, so I decided to do the basic things everyone else's done to rule out possible causes. Such as:

- make sure the alternator is cranking at the right voltage (check)
- make sure the wiring harnesses aren't corroded (check, amazingly)
- make sure the battery cables are in good shape (check)
- make sure the ABS sensor are working (can't really check this, but the connections are clean)
- give the ABS a run for its money (doesn't work when light is on)

While poking around, I noticed the latch which secures the ABS module in its housing was slightly lifted. I tried to lock it down, and it made a familiar "gritty" sound: dirt. At least with computers, sometimes re-seating a CPU or memory chip or expansion card will fix random/strange problems with those components, especially when dirt's worked its way into the connectors...figured that might be the case here.

So I removed the negative terminal from the battery, lifted the latch, pulled off the top of the harness/module assembly, and cleaned everything out with electronics cleaner. Left to dry overnight. That was three days ago, and the light hasn't come on again. Won't have a chance to test the traction control until I make the trek to Albuquerque this weekend (mountains, icy this time of year, always), but the ABS seems to work. That or something's having a major conniption fit when I slam on the brakes.

My question: was the problem likely a shoddy connection in harness/module connection? Or have I probably just shorted the whole thing out?

[precopster]

Anything is likely and it's always good practise to make sure that comnections are clean. The ABS system does a self-test at start up so if you killed the system (which is extremely unlikely) it will flash a Brake System Failure light which looks like a red exclamation sign.

The unit may need resoldering. There is a DIY here on the forum on how to do this. It's not hard and you will save some dollars. If you're not keen on that Matty Moo can repair your unit for you for a reasonable sum.

[Ozark Lee]

You likely fixed the problem. The '93 to '95 ABS system has an entirely different module than does the '96 and on. While the later versions have a near 100% failure rate the old system rarely has a module problem. The beauty of the '95 turbo is that you have both OBD-I and OBD-II and you can use port A-3 on the underhood diagnostics to figure out what the system is mad about.

If the module or the pump motor does turn out to be bad they can be found on eBay dirt cheap. Since they fail so rarely there isn't really a market for them.

...Lee