Trailblazer Trouble


Old 11-16-10, 07:33 AM
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Trailblazer Trouble

I own a 2004 chevy trailblazer.I disconnected the battery to do a minor repair with my interior console.after reconnecting the battery the vehicle idles erratically with AC turned.This has been since yesterday.Is there something that needs to be reset? Please help.
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Old 11-16-10, 09:30 AM
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Not sure of yours..but most newer vehicles need to "re-learn" after a battery disconnect of any length of time. There should be something in the manual..but it normally involves driving at certain speeds and for certain distances.

To get accurate should post complete details of the vehicle. Engine, drivetrain (2 or 4 wd)...etc.
Old 11-16-10, 11:31 AM
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The PCM uses non-volatile memory to track the IAC position when the engine and PCM are off. PCM off means battery disconnected. IAC values differ from vehicle to vehicle. The PCM has to factor in the condition of the sensors, air and vacuum passageways. Whenever the PCM loses battery power, the IAC position will clear. When this happens, or when sensors are changed an “idle learn” procedure must be done .

Turn the engine off and remove the key.
Open the circuit to the PCM for 20 seconds.
Close the circuit after 20 seconds.
Start the engine and let it idle for 10 minutes.
Shut the engine off for 20 seconds.
Start the engine again and let it run for 5 minutes.
Shut the engine off again and you're done.
Old 11-16-10, 12:16 PM
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Well there ya go...simple. I knew someone would have the real info.

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