Pontiac Sunfire



September, 20, 2007 AT 8:56 AM

I have a 1999 Pontiac Sunfire, 2.2L i4, automatic trans, no, A/c with 104,593 Km.

Do I need to have the ECM relearned even if I have had the unit reflashed to my specific Vin #?

I bought an ECM that was reflashed for my Vin # and when I installed it, it ran but threw up tranny codes, no tach, battery light on, and stall out in drive. I was told I need the car relearned as well. Does this sound right?

4 Answers


Service Writer

September, 20, 2007 AT 9:06 AM

First set the password. Try to start it, leave the key in the on position. Anti-theft light will blink for 10 munties. When it stops turn and remove the key. It can then be started. We can go from there.

There is a recall on this computer and could have been replaced by the dealer for free.



September, 20, 2007 AT 10:07 AM

I had no problem starting the car. The car started with the reflashed ECM. The tach did not work, the speedo was all over the place, the battery light was on, and so was the CEL.


Service Writer

September, 20, 2007 AT 5:55 PM

I never said that you couldn't start it.



September, 21, 2007 AT 8:56 AM

I think there is a bit of confusion in regard to my question.

I purchased a used ECM that was reflashed to my VIN number. When I installed it, the car turned over on the first try. Right away, the tach was not working but the speedometer was acting like the tach (give a little gas and the speedo would rev up and down), the battery light was on, CEL light came on (scanner came up with P0785 and P0740-tranny codes). The anti-theft light never came on. I was able to reverse all over the place but going into drive caused it to stall.

I understand about the Passlock system. I had to replace a battery about 3 years ago and went through the procedure to get it running.

So to reword my question; should an ECM that has been reflashed to my specific vehicle act his way (causing codes, strange gauge reacion, etc.) Upon installation?

From my experience, it would seem to me that the ECM is bad and if there is a recall like you stated, it is possible I got another bum computer. The seller feels the ECM is bad becasue he stated it should not start up on the first try with a Passlock equipped car.

I just want to make sure that before I go to the trouble of returning this ECM that I am not overlooking something.

Thanks again

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