Need help with ECM/PCM???

[turbov6joe]

My dad's 1999 Regal GS is having issues with an intermittent stutter/hesitation while at highway speeds. It almost feels as if the TCC is locking/unlocking. If your roll into the throttle more, the issue goes away and it pulls hard. He took it to a shop and they said that the PCM is bad and needs replaced. My questions are:

Is there a difference between the PCM and ECM on this motor?
Is the PCM different on the FI/NA 3.8's?
Does it have to be programmed if I buy one from GM?
Does anyone happen to know the part # for the PCM?

TIA

 

[1987GNASTROROOF]

PCM or power control module is the same as an ECM electronic control module,if you PM I can problaby find that ECM part number tomorrow.


Posted from the TurboBuick.Com mobile app

 

[turbov6joe]

PCM or power control module is the same as an ECM electronic control module,if you PM I can problaby find that ECM part number tomorrow.


Posted from the TurboBuick.Com mobile app

Ok, thanks. What confused me was that several different parts places were listing both a PCM and ECM, but didn't have part numbers attached to differentiate them.

 

[turbov6joe]

The number I'm coming up with is: 9361735
O'Reily's website says that the ECM needs to be programmed before using...I'm wondering if my local GM dealership would be able to flash it???

 

[jdredd]

The Serv # stamped sticker on the PCM should be 16236757

I would be interested how the shop decided it was the PCM that was bad. Did they use a GM Tech II tool to test it?

The PCMs are pretty sturdy and when I worked for DHP for a few years flashing and shipping the PCMs, only time I had
issues was due to salvage yards beating the crap out of them and pending the pins or beating the crap out of them (all dinged up, case cracked, ect)

These don't seem as bad as the old PCMs that used the smaller daughter board cards.

Dealer should be able to flash it... but i'd just either find one on car-part.com or ebay that came from a 98 GS, or find a local person to flash it for you.
Most dealers will kill you on their services.

The PCM hardware is interchangable, but the OS/Code flashed on them is not. So getting the proper code on there is a must.

My best guess is, if it feels like the trans is being stupid,. it probably is your problem. TCC solenoid goes crappy on these and eventually will start setting a DTC code.

Considering its a 98.. and if never been rebuild/replaced, its time for some love...

If in a crunch, check your in box...

 

[murphinator]

its a tough pcm I agree with jdredd .... I am sure someone on the regal board is parting out a 99 , I would buy a used pcm if you cant find one then get a pcm from zzp or intense and just ask them to leave the tune stock if you don't want it modded. I don't even want to know what a dealer wants for a pcm , a forum sale should be $75 or less shipped. I just sold a 98 pcm to a guy on here with some other items so he could reduce the core charge at zzp , they will accept any year pcm as a core as long as it is a core they would be able to resell.

also as jdredd mentioned the solenoids are a common cause for trans failures , replace all 3 while the side cover is off tcc (torque convertor clutch) , shift solenoid , pcs (pressure control solenoid)

 

[machinegun]

I would before replacing the PCM verify a couple of items.

The supercharged cars along with the emission mandates have a tendency to be pretty lean.
This puts an extra load on the ignition system which causes ignition system failures.

So before doing the PCM I always put fresh plugs prefer non platinum, fresh wires, fuel filter and check the fuel pressure.

Check the PCM for any miss fires. The 99 and up are usually pretty good at flagging them. If there are any clear them re drive with the above items done. See how the car behaves. I have resolved almost 80 % of these types of issues just by doing this. After that you may need to replace the coil packs which can be had from summit pretty cheap and they are a 5 min replacement. Even if not needed not a bad idea anyway.

After that if you are still having an issue find some one with HPTuners who can scan the car while driving and look at the live scan and go from there.

If you are close to me I would be more than happy to help.