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2003 transmission into older 99-02???

Reverant GTP

Reverant GTP

New member
Not a lot of information out there about this. Most say its not worth the hassle etc. I just want to know what all this hassle involves? It sounds like I just need a 2003 pcm and use my external range selector and I'm good to go. Can anyone confirm this? Is the pcm itself different or can I just flash the 2003 calibration onto my 2002? Thanks for the help guys.
 


You need to use the external selector, 2003 PCM Hardware, and a PCM Calibration that matches the year of your car.

I ran a 2003 Trans in my 99 Regal GS for years with that setup, no issues at all!

-Rob
 
What do you mean a pcm calibration that matches my car? I finally am getting the transmission this weekend so hopefully in the next month or so I'll have the swap done. It's a 2003 gt trans going into my 2002 gt. I had the guy grab the harness and pcm too as I'm not sure what I'm going to need and not need. I still see people saying just the 2003 pcm and other saying i need the harness too from the 2003.
 
I was just going to throw the PCM in and trans in to see what happens. Then pobably unlock it and copy the zzp 1.0 tune for the engine side and leave the trans settings alone for the most part. As I don't know how much different, nor what I'm looking at in the pressure tables.
 
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You need the 03 PCM, and that should work with your car, no changes.

You will also need to move the trans range switch from your trans onto the new trans. This lets you re-use your wire harness.

Other then that, it should be a bolt in and go.

-Rob
 
^^That.

And if you don't follow those cues, it'll go into "limp" mode if you will and not shift from 2nd gear. Ask me how I know.
 


Bills post there seems to be how to add an external range switch. Not how to run a newer trans in an older car.

-Rob
 
that how to is for the newer to older style trans. newer has the electronic switch, the older has the manual switch. so if you need to flip flop one way or the other you swap that pnp switch.
 
Thanks Rivman for the help... Just curious do you think I should still be able to use the trans setting from the 02 zzp tune? Then again i could see the 03 being quite a bit different since it a different calibration to control the tranny.
 
I was just aware that you could swap channel plates/wiring harness, and the external range switch and it would work in an 02 or earlier car. That's everything that changed electrically so the original PCM would work

Sent from my Nexus 7
 
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