I've been troubleshooting an ASC/TRAC unavailable issue for the past week or so. After testing all the circuits from the harness at the module I'd pretty much pinpointed the issue as a module failure. Was planning repairing the module this weekend. Here's the fix - we had some nasty storms moving in on us last night so I moved the car to a safer spot. I get in it this morning and I realize I'm staring at a clean spedometer - NO Warning Messages NO Amber light. Before I got no response from the TRAC OFF button on the console (no light). This morning it lights up and all looks good. Just wondering, part of my circuit check was a physical inspection of each sensor and leads. While I was there, I also cleaned each sensor head. After that I checked resistance at the module connector and all checked out, but I still got the warning message and amber light. Just trying to figure out why they warning disappeared days afterward. The module is sealed so I wouldn't think humidity is bridging any bad solder points on the board.

 

So what do you think changed? It dried out? I don't get your fix?

 

I get ASC/TRAC messages all the time in damp weather or after a rain storm. When things dry up for a day or so, the messages go away. Sounds like the same deal as bluerdog. I figure there has to be some connection that has a leakage short when it gets damp, but I haven't figured out where yet. So far, it's just an annoyance. I do have to be sure that I take my car in for its state inspection on a dry day! They don't like error codes...

 

Oh, and if it starts raining after a dry day, and I'm driving in it, it takes 15 or 20 minutes for the ASC/TRAC to light up. So clearly some moisture takes a bit to soak into something.

 

I'd be wondering about moisture possibly getting into one of the link leads from the body to the wheel hubs. That would probably be accompanied by a C11xx code; but they can't be read by most generic scantools. Those links are constantly flexing up and down and twisting when the wheels turn. They can fracture internally.

Cheers,

 

It seems to me when it's wet on the road is when you would WANT ABS brakes!
I have to get my car smogged, and I have to deal with the light before I go.