Mechanics

CHEVY ECM RESET.

2006 Chevrolet Cobalt

Computer problem
2006 Chevy Cobalt 4 cyl Front Wheel Drive Automatic 38000 miles

Hey I have a 2006 Chevy Cobalt with 38xxx miles on it. A couple months ago GM called and said there was an ECM reprogram campaign. Thinking it was neccessary I took it in and had this done. After I did this I began to noticce changes in the cars performance and fuel consumption. Prior to the reprogram I was very satisfied with the power and response from my little car, after wards the transmission will not shift at times and the engine is often unresponsive or late to my pedal commands. ALso my gas mileage went from 32 mpg to 26 mpg after the reprogram which is suspicious because that is when the new EPA estimates came out for gas mileage. Is there anyway I can reset my ECM to the original factory settings and undo the reprogram or should I buy a new ECM.
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M0rdecai89
January 20, 2009.




Hi, did you talk to the dealership about your problems? What did they have to say?

Even if you buy a new computer, it may have this update already installed. It may not make any difference?

JDL
Jan 20, 2009.
The dealership insisted this was not true and that the reprogram was correct. They also wanted 100 dollars just to look at it. So there is no way for me to reset the ECM to factory settings? Can the dealership restore original settings?

Tiny
M0rdecai89
Jan 20, 2009.
I did look at some bulletins for your vehicle. I did see a service update, under 8 years/80K, warranty. Not sure if I was looking at the proper update?

You might talk to another dealership, ever who answers the phone, ask for the service department, talk nice, explain your problem. See what they have to say.

If the diagnostics showed my work caused the problem, I wouldn't charge the diagnostics. If the diagnostics showed an unrelated problem. I would charge for the diagnostics. I don't know how a dealership would handle problems like this? I know a lot of shops charge around 100 bucks or more for diagnostics, even if they don't fix the problem.

JDL
Jan 20, 2009.
So there is no way to reset the ECM to factory settings myself, it would have to be through the dealer?

Tiny
M0rdecai89
Jan 20, 2009.
That's the only way, I know. I'm not sure they could undo it, or would.

JDL
Jan 21, 2009.
Why do some posts say you can reset an ECM by disconnecting the positive battery cable for 3 mins and then tapping it on the post 3 times? Is this only true on some cars?

Tiny
M0rdecai89
Jan 21, 2009.
I've never heard of the tapping part? I have heard of taking a cable loose to erase codes. If a service bulletin told me to take the cable loose for some diagnostic procedure, I would. I can't say that taking the cable loose will help or hurt?
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JDL
Jan 21, 2009.

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