96 Sunfire ECM on 1996 Pontiac Sunfire

Hi I just recently replaced the ECM in my 96 Sunfire and now my gauges are going crazy! My speedometer is jumping all over the place in idle and is registering way too fast when Im driving, causing my trans to shift through the gears too fast, Im in 3rd gear when Im going about 20 but the speedo says im doing 60 or so.. Also check oil light is on and oil is not low, and coolant light is on but also not low on coolant...Is it possible I got a bad ECM (bought it from AutoZone) or is there something else I should be looking at? P.S speed sensor was also recently changed

by in Warren, MI on March 11, 2011
2 answers 6 comments
ANSWER by on March 11, 2011
sounds like the ecm wasnt calibrated correctly so it is throwing everything off and the ecm cant correct it. i would take the car to the dealership and have diganostic run on it to verify if its a bad ecm if so get your money back and get one through the dealership then everything is covered under the dealership warranty.and they have to fix and replace it while under warranty. its best to spend the money on the dealership. Rather than having to replace it all the time and wasting money and time on fixing it. yourself
COMMENT by on March 11, 2011
Thanks for the advice...I had Autozone order another 1 since I cant afford to take it to the dealer right now, but if that doesnt resolve it I guess Ill have no choice...The dealership wants $100 just to look at it and if I do need the ECM itll be another $400...so Im trying to go the cheapest way possible at the moment...I do appreciate the input tho :)
COMMENT by on March 11, 2011
your welcome and good luck
COMMENT by on March 15, 2011
*****UPDATE****** I chaged the ECM once again and....same problem!!!! GRRRRR! Now Hubby thinks the eprom needs to be changed but hes not sure if theyre interchangeable? Any input would be helpful since Im at a brick wall on this 1...ready to just scrap the car but I really need it to get my little man back and forth to school :( HEEEEEELLLLLLLLPPPPPPP Please!!
ANSWER by on March 11, 2011
It is common after changing an ecm that you would need to let vehicle idle, sometimes in gear, for a period of 20-30 minutes to allow it to relearn and adapt to the vehicle operating systems.
COMMENT by on March 11, 2011
Thanks, Im gonna try that-hell id stand on my head and recite poetry if itd work at this point! lol
COMMENT by on March 11, 2011
If you do that would you please take pics and tell me where it is at on you tube...lol...no I mean it really...
COMMENT by on March 12, 2011

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