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Discussion Starter #1
I've been having a problem for quite a few months now. I usually don't have any issues with in-town driving. Mostly highway only. I have been getting a Service Traction Control message on the DIC. It only comes on after an hour or two of highway driving, or whenever I punch the gas to pass someone. When the message displays, the car will tend to shift harder, but there aren't any other issues. A lot of the time, the message will go away and the car will return to normal. Occasionally the message will stay and I have to turn the car off to get it to reset.

I've had a mechanic diagnose the problem and what he came up with was the BCM was bad. Weird thing is when he was test driving the car, he had a scanner tool hooked up and was able to reproduce the exact symptoms that I had, but also had the gauge cluster fail a couple of times, and one or two other things that I don't recall at this time. He experienced issues that I never did.

I can see the possibility of the BCM begin to fail after warming up, and possibly failing more with a scanner hooked up, but I more often than not, get the message only after punching the gas. Sometimes, very little acceleration or a hill will trigger the message.

There are two very rare instances where the Service Brake Assist warning showed up too, but has not happened for quite awhile.

I was quoted about $600 to install and program a new BCM, but I'm not 100% confident that the problem would be solved. Any thoughts?

PS. I've been having the Service Air Bag message coming on and off no matter what the driving conditions. Started happening around the same time. Not sure if it's related or not, but I'd rather tackle one issue at a time.

Thanks for any help.
 

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Not sure on the air bag lamp but your traction control and ABS get information from your wheel sensors. And there are some reports that a fault from the wheel bearing will cause the lamps to light up. Even though not programmed into the PCM or BCM that the ABS wheel speed sensor can pick up that the bearing bad by the wheel having a very small amount of side play in it and will trip the lamp(s). IIRC the sensor and bearing are one piece.
 

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Really need to know the exact code that was tripped. Most auto parts stores can read and tell you the code for it should still be in the PCM/BCM memory.
 

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Discussion Starter #4
A lot of what I've read seems to point to a bad bearing. I did ask the mechanic if the wheel bearing could be getting bad. He said that there was very mild play, but not enough to worry about at this time. I am unable to hear any noises coming from the hub. I still am a little confused as to why it only happens when I'm driving on the highway for an hour or so. I can go quite awhile with just in-town driving without having a problem at all and that includes mild driving as well as hard accelerations and very frequent use of the traction control on icey roads.

I'd like to poke around on the car myself, but with these sub zero temps up here in North Dakota, it's just not fun being outside. I'd also like to mention that my experience working on cars is very limited. I'll usually try to do something myself, but I usually don't know what I'm doing.

As for codes that the car is throwing, I have no idea what they are and never asked the mechanic. Whenever I get a chance, I'll try to have it scanned at a parts store.
 

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He said that there was very mild play, but not enough to worry about at this time. I am unable to hear any noises coming from the hub. I still am a little confused as to why it only happens when I'm driving on the highway for an hour or so.
Any play in the bearing is bad, with play in it it will go bad soon. Waiting until hearing noises before replacing it could lead to a major breakdown while on a trip.

I recommend changing the both front bearing first before suspecting that the BCM is bad.

Why at highway speeds right now, I just don't know. Possible that when you hit the accelerator that the front of the car lifts and may be changing the position of the bearing in relation to the speed sensor.
 

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Discussion Starter #6
Kind of resurrecting this thread, but I was going through some old receipts last night and I took a closer look at the receipt I had from the mechanic. Turns out that they did have the error code printed on the receipt. It is a code U1040 (DTC U1040 Loss of Communications with TCS). I'm still not completely convinced that the BCM is the problem, but as soon a spring makes it's way up here and the snow melts sometime in July, I will inspect the harnesses myself and go from there.
 
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