C5 PCM issues help please
Thread Starter
Cruising
Joined: May 2018
Posts: 12
Likes: 0
C5 PCM issues help please
I had my c5 quit last fall. Car eventually starts and runs, but most gauges are inop. Dealer diagnosed as pcm. Chevy dealer has had it for 2 months. I had my factory PCM professionally rebuilt/repaired. The dealer bricked that one. I provided them 3 more used pcm’s which they bricked all of them. Took it to another Chevy dealer yesterday that said they could program my new (used) pcm. They called 5 hours later and said GM no longer supports programming 98 corvettes. I’m worried they tried and bricked this pcm. Questions are, if GM says they don’t support programming, is there anyone that can guide me on getting it programmed? Also, I’ve just been buying the same part number PCM. My c5 is manual. Do I need a specific pcm or same part number will work? Thanks.
Drifting
Joined: Jul 2006
Posts: 1,293
Likes: 60
From: Somewhere out there
Find yourself a local dyno shop. An experienced tuner with Hp Tuners can take a Gen 3 ECM and have you car running in about an hour. It's not a difficult thing to do at all, typical dealership quacks.
Thread Starter
Cruising
Joined: May 2018
Posts: 12
Likes: 0
thank you. I found someone with hptu er that is willing to give it a try. Seems easy enough. I don’t understand why a Chevy dealer can’t get this done.
Drifting
Joined: Nov 2017
Posts: 1,393
Likes: 303
Are the PCMs getting bricked during programming, or is there something that's damaging them electrically when the PCM gets plugged in?
Upgrading to a later PCM sounds like a good idea, there are lots of ways to program those, including an open source project that I worked on (PCM Hammer), and they're plentiful.
Might as well upgrade to a 2004 PCM while you're at it, they cost only slightly more and they can be tuned for flex-fuel if you add a sensor.
I've never done the re-pinning myself but it's fairly common. Anyone know if the pins are interchangeable?
Upgrading to a later PCM sounds like a good idea, there are lots of ways to program those, including an open source project that I worked on (PCM Hammer), and they're plentiful.
Might as well upgrade to a 2004 PCM while you're at it, they cost only slightly more and they can be tuned for flex-fuel if you add a sensor.
I've never done the re-pinning myself but it's fairly common. Anyone know if the pins are interchangeable?
Safety Car
Joined: Mar 2005
Posts: 3,759
Likes: 1,217
From: Wisconsin
Thread Starter
Cruising
Joined: May 2018
Posts: 12
Likes: 0
They finally admitted they were bricking them during programming and said if I brought just one more they were “90% sure they could do it”. I rebuilt my first one which they bricked. I sent it in again to be repaired and the pcm repair business said it was now not repairable.
Drifting
Joined: Nov 2017
Posts: 1,393
Likes: 303
You can repin a 99 to a 01-04
https://www.corvetteforum.com/forums...m-success.html
https://www.corvetteforum.com/forums...m-success.html
PCM upgrades are definitely a thing though, for C5s and Camaros. I haven't done it myself but I met a guy locally who did it, and I've seen a handful of threads from people who did it.
Safety Car
Joined: Mar 2005
Posts: 3,759
Likes: 1,217
From: Wisconsin
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Instructor
Joined: Dec 2024
Posts: 125
Likes: 73
From: Alexandria VA
Call Intelligent Performance and they can set your car up with a P59 PCM, from 2004. Or provide you with an alternative if yours cannot be converted. I have a 2001 Z06 with a P59 PCM from them.
Harrisburg, SD
605-681-6787
Jeremy@intperform.com
Harrisburg, SD
605-681-6787
Jeremy@intperform.com