What programming required for New PCM

CHABUNGA

MEMBER
2002 CHEVROLET TRAILBLAZER
6 CYL
4WD
AUTOMATIC
89,000 MILES

Here's my story. Scan indicated I needed a new PCM. Called dealer he wanted $700 parts $200 labor. For the hell of it, I called local salvage yard. They had one for $25. Seemed like a good bet to me. It was actually from an Olds Bravada, but the part number the same. Swapped it out, went through the security relearn and it started. What really surprised me was there are no extra lights (error/warning) on. The only thing I notice is that when idling in park the RPM's vary up and down. So, my questions are:
1. What programming do I need?
2. What will the dealer charge me?
3. What happens if I don't get the programming?

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

This generation of GM products do not require programming if you are installing a PCM that is already programmed.

So, you do not need the PCM programmed on this. Your issue is most likely a vacuum leak that you didn't know you had, or the throttle body needs to be learned to the new PCM.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

To relearn the throttle body, I would start with checking for codes.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

I am attaching the crank and throttle learn procedure below.

Please run through this and let me know if you have questions on this.

Thanks

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