NOT your usual ABS/TRACS failure... (long)

[flaco]

96 850 GLT 37k miles - Atlanta, GA

The car had the ABS/TRACS lights on and off for the past year. The car was taken to a volvo dealer (Orlando FL) and the module was replaced with a new one ($$$). A month later, the problem came back. They changed the module again for free, under the prev repair warranty. Now the lights are back on, so Ive dissasembled the module (last replaced in may 07!) and needless to say, everything looked NEW. I resoldered the connector pins just in case, sealed the unit, but my problem remains.


In the past week it has become even worse. Sometimes the lights will be off when I park the car. When I turn the car back on, the ABS and TRACS light up as usual, and sometimes (Id say chances are 50/50) they remain on, without even starting the engine.

At the next restart sometimes they go off after the module runs the self test when I hit ~15mph.

Sometimes the ABS will activate itself and the pedal will vibrate under light braking and coming to a stop.

So far Ive been able to read the engine, cruise and climate error codes off the OBDII connector with a led, but seems the ABS unit is not readable without the volvo scanner.

I've now moved to Atlanta, so I cant take my car back to the Orlando dealer who changed the module twice. I know I need to read the error codes, but I really dont have the $ to go to a local dealer for some time...

SOOOOO... any tips? after the module failure, whats the next usual suspect? Or even better, anyone in Atlanta who can read the ABS codes?

thanks for all and any help!

[CarVolvo]

Have you cleaned your sensors .. specially the ones on the front wheels?

They are located just above the axles. They occassionally need cleaning because they gather road dirt and brake dust.

I guess the question is.. are your tracs and anti-locks working after the module change. If they are then it could be a number of things because its not only the module.. i could also be the abs pump.

However, if they are working and your still getting this annoying lights on syndrome, i would definitly check the sensors and make sure they are connected properly and clean!

[flaco]

Yes, whenever the lights are off, tracs and abs works. Tried them a couple of times in the last showers we had.

Of course, when the lights are on, both systems are down.

[JRL]

You have a bad wheel sensor.
Not too common but it CAN happen
I'm very surprised the dealer didn't test the sensors the 2nd time around

[pfeener]

I'd bet money your module is bad again. The key here is when they replaced the module the lights went out for a time. If it were a sensor or something else, the symptoms wouldn't have changed. These modules are so flaky that sometimes new ones will fail within a short period of time. I would remove the module you have in there and send it to victor and have him rebuild it.

Here's the link:

http://home.earthlink.net/~vicrocha/

[flaco]

Well... when they replaced the module the 2nd time their fix lasted for a week or so? And the car was mostly parked so I couldnt really tell....

And I did opened it, and re-soldered the pin connections other members have had luck with. I recon its not impossible but a long shot for sure...

The best would be to read the codes, but since I dont have $ or a way to read them...

Anyone knows what does the ECU tests for when it's first turned on? I looked in the donwload-able manual, but it's for a 95 and mine is a 96 with the ?new? ecu so...

[JRL]

Autozone=free code reading.

[flaco]

engine codes yes,
ABS codes NO
already tried that.

[JRL]

engine codes yes,
ABS codes NO
already tried that.

MOST of the time, the ABS doesn't throw a code as it is not part of the engine management system.
The times that it does, it can be read with a simple scanner, yours has no codes to show

[flaco]

Doesnt makes sense to me, that while ABS and tracs lights are on, no codes are shown on the cheap autozone reader?

Or is it, like I said, that the cheap readers cant read ABS codes??