97 gtp pcm ?

[SarasotaGTP]

If this is in the wrong spot please move it but I was not sure where to post this.

I have a 97 GTP that is/was stock and I thought that my PCM had died based on several things. So I got a different one that turns out not to have been originally from a 97 GTP but when I run the numbers off the PCM it says it was from a 97 Olds Cutlass. THe PCM had been tuned with the following changes

3-1 and 4-2 skip shifts
- Transmission line pressure increased
- Shift points moved (5800-6000rpms)
- Fan turn on points altered:
- Torque abuse modes are modified to eliminate bog at launch
- Trans shifts are quicker
- 185 degree turn on
- 2 minute fan on at key-off\
- MAF calibration adjusted for proper operation and yea
- Removed “40MPH WOT lag”

The PCM installed in my GTP fine and actually started my car right up and after running for maybe 10-15 minutes or so it smoothed out and I began to drive it. The car ran like a beast (in a good way) and had never felt stronger or faster although I did not run it past about 75mph with the "new" PCM. It shifted very differently than the stock PCM and actually threw a code P0748 which is a pressure control solenoid. I am not one to ignore codes and stuff so I decided to put my old stock PCM back in the car to see if it would work. It did. The P0748 is a history code but not currently a DTC with the original PCM in place.

My question is two fold. Is there a reason not to use the PCM that says it is from an Olds Cutlass myself? I really liked how the car ran and the fan cut-in but don't want to damage the trans. Is it just tossing that code cuz the stock solenoid is basically saying "hey why am I not working like I am supposed to"? or is this a potential BOOM? Also if I can't/should'nt use it I would want to sell it but I don't want to sell it to somebody without disclosing the issues first.

Sorry for the novel but I hope this makes sense. Thanks!

[Grimsin]

97 olds cutlass came with a 3800 series II supercharged? i cant find any links or websites that state this... id be worried about it have different gear ratio also.

[SarasotaGTP]

Here are the numbers on the PCM and this is what I ran on google

serv. no. 16217058 caww and
hdw no. 16218070 caww

It lists some other possibilities so I am not 100% sure it was an Olds PCM but that is what the majority of info came up as. Sorry I should have said that in original post but was trying to keep it as short as possible. Failed in keeping it short as it was but I tried.

[darkhorizon]

This thread is going to be nearly impossible to answer without you knowing what OSID you have on that pcm.

To find that information out you need to find someone with a tuner or something.

[SarasotaGTP]

I was thinking of maybe doing some of the same things to my stock pcm that were on the other one so I guess all I need now is to find a person who can tune near Sarasota and have them check the other pcm at the same time. What exactly should I ask them to look for in the other pcm that will help identify if it is safe keep or sell to someone and be able to disclose the important stuff to a potential buyer? Sorry but I have no idea if I am even framing my question right so I hope that made sense. Thanks.

[jteske88]

hey if it dont go through we can trade a stock 97 for that modded one, well maybe let reptile touch it first lol

[BillBoost37]

Many of the 97 pcms are pretty much hardware alike. The OSID assigns the pinouts and what wiring to expect in the vehicle. Therefore you should be ok. The fact that the pcm saw something with pressure is likely based on the new one learning the adaptive shifting etc. It saw the pressure wasn't perfect, the old one apparently saw it as well, and somehow (likely adapting) was able to move it to a history code instead of current.

[SarasotaGTP]

Thanks Bill. I've seen info like that various places online but coming from you that makes me feel better. It was tuned by a very good tuner so I figured it was okay but didn't want to ignore things in case it wasn't.

[SarasotaGTP]

Alright, here we go. So I listened to Bill on another problem and changed out the battery cables and my LTFT's are right on now but my idle is still a little bouncy. I was thinking CPS but I changed the PCM's again to see if the battery cables change would make any difference ( I know dumb but i had the parts to swap and see) and it did not change anything from before. The tuned PCM runs like a beast and the harsher shift points still worry me a little but I am confused cuz my idle was smooth as glass with the tuned PCM no rpm bounce at all. What gives? Any ideas? If it was the crank position sensor then wouldn't the rpm's bouncing exist on both PCM's? I am so confused. If there weren't so many GTP's for sale right now i'd throw mine up too since a 97 is only worth scrap though I guess I better throw more time/money and energy at this heap.

Okay throw some wisdom at me. Thanks!