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Pontiac Repair/3.8 Crank Position Sensor


When replacing the CPS on a 3.8 engine, is it necessary to bring the vehicle to the shop for a formal "re-learn" or flash of the PCM?  The process of replacing the CPS seems simple enough.  It doesn't appear that anything gets disturbed or any special settings or adjustments are altered.

ANSWER: Hi Colin:

No a crank sensor is just plug and play Per say. BUT if it's replaced it should be relearned. It depends on the model year of the car. older 3.8's nothing has to be done. newer ones say 1996 and up they need to corolation learn. It helps the ECM determin if there are any misfires. If you don't do it you could get false misfire counts or it could cause a misfire to occure. Take your chances.
Good luck :-)

---------- FOLLOW-UP ----------

QUESTION: Are there any other sensors that, if replaced, would require this "relearn" procedure on a newer (2002) 3.8 vehicle.

Is this "relearn" procedure required when an engine is partially tore-down, when replacing head gaskets or a timing chain, for example.

Edit Thank you for the donation! :)

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Todd Puccio


General auto repair,electrical issues,driveability issues,anti-lock brakes,SIR systems,HVAC,engine performance,Gm specific. I have worked at my current dealership since the 1990 model year anything much older than that I have limited exposure to. I do not have very much transmission experience so those question you may want to ask of another expert. When you send me a question let me know the exact make/model/engine and year for the car or suv you have it makes it easier to answer the questions that way. If your happy with the answer I gave you please feel free to Donate. This is a free service to you and I am not compensated at all by this web site. I have 22 years of experience to share with you and my knowledge wasn't free to me. I had to pay for my education.


Experience in the area: I have been a technician in GM dealerships for over 22 years and I am a ASE master technician. I work at a Buick and GMC truck store Previously I worked at a Pontiac GMC store for 18 years. I Served a a lead technician when dealership was on a team system. I just recently moved to a Buick,Hummer,Saab Store when my franchise was purchased by this dealership. Organizations: ASE master technician


Education/Credentials:High school diploma,2 year vocational school degree 2 year college degree. Associates degree in applied sciences (auto technology)Awards and Honors: GMC master technician

Awards and Honors
Master GMC truck technician Master ASE technician in 9 categories

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