Thread: Mind-Boggling Scenario. 3.29 Gear Ratio Programmed to PCM. 3.03's In transmission.

Results 1 to 6 of 6
  1. #1 Mind-Boggling Scenario. 3.29 Gear Ratio Programmed to PCM. 3.03's In transmission. 
    GT Level Member Brian99SE's Avatar
    Join Date
    Dec 2011
    Location
    Cadiz, Ky
    Posts
    242
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    So, Story. My transmission dropped out of my 1999 Grand Prix SE. Just so Happened I had a 30K Mile transmission at work that I could have at no cost. So I swapped it in. It was out of a 98 Buick Park Avenue.

    As I see it. It has 3.03 Gears in it. Where as my Factory transmission has 3.29's. All is fine and dandy. Except one issue, The PCM Sees the transmission as its slipping due to the different gear ratio. Altho its not truly slipping. It is Pushing full line pressure to the solenoids. Almost as if it has a strong shift kit installed.

    I can, And Have dealt with it for a while but. Out of curiosity. I attempted to use the PCM out of the Buick to see if it would work. Surprisingly my car started with the Buick PCM. Altho they were visually different the Connectors were the same. But the bad. My Grand prix was missing/Running on 2-3 Cylinders. And my fuel gauge read empty.

    Is there anything I can do to use the Buick PCM. Or Anything I can do to my factory PCM to make it shift like it should? Kinda gets old slamming into gears. And being able to break traction going 60 on a wet road punching the gas.
    99 Grand Prix SE-Blue CAI, 3.03 GR Transmission, U Bend Delete.
    time to call the exterminator
    Reply With Quote  
     

  2. #2 Re: Mind-Boggling Scenario. 3.29 Gear Ratio Programmed to PCM. 3.03's In transmission 
    Moderator dsmuts's Avatar
    Join Date
    Feb 2011
    Location
    Coldwater, OH
    Posts
    15,758
    Thanks (Received)
    1
    Likes (Received)
    1
    Dislikes (Received)
    0
    I'm guessing the buick had the 3800 and your se has the 3100? They have different firing orders. You need to get your pcm tuned for the gear ratio change.
    98 GTP modded 1.9's, sd headers, 3.4", zzp 1.0 230K miles scrapped.
    04 Comp G zzp stb's, UMI ta's, Speedbuilt sways, bully flo heads, XP, zzp headers, fsic, thrasher shift kit, 60#, 2.6" corsa 2.5", Inferno hood
    01 gt z7 turbo tep trans zzp motor
    08 g8 gt cam exhaust 11.87@118
    Reply With Quote  
     

  3. #3 Re: Mind-Boggling Scenario. 3.29 Gear Ratio Programmed to PCM. 3.03's In transmission 
    GT Level Member Brian99SE's Avatar
    Join Date
    Dec 2011
    Location
    Cadiz, Ky
    Posts
    242
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Both cars are 3.8
    99 Grand Prix SE-Blue CAI, 3.03 GR Transmission, U Bend Delete.
    time to call the exterminator
    Reply With Quote  
     

  4. #4 Re: Mind-Boggling Scenario. 3.29 Gear Ratio Programmed to PCM. 3.03's In transmission 
    Turbo is the way to go. Fivefingerdeathpunch's Avatar
    Join Date
    Sep 2009
    Location
    Rogers, MN
    Posts
    21,022
    Thanks (Received)
    21
    Likes (Received)
    45
    Dislikes (Received)
    0
    You must reprogram your grand prix PCM, there is no other way around it.

    As in with a tuner.

    SMGPFC Member #1
    Reply With Quote  
     

  5. #5 Re: Mind-Boggling Scenario. 3.29 Gear Ratio Programmed to PCM. 3.03's In transmission 
    GT Level Member aligater's Avatar
    Join Date
    Sep 2008
    Location
    london ontario canada
    Posts
    218
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Maybe contact Dave at TEP but can't you not just swap the diff and housing. Pretty sure that's the only thing that's different.
    Reply With Quote  
     

  6. #6 Re: Mind-Boggling Scenario. 3.29 Gear Ratio Programmed to PCM. 3.03's In transmission 
    GT Level Member Brian99SE's Avatar
    Join Date
    Dec 2011
    Location
    Cadiz, Ky
    Posts
    242
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Quote Originally Posted by Fivefingerdeathpunch View Post
    You must reprogram your grand prix PCM, there is no other way around it.

    As in with a tuner.
    You or anyone else know of anyone in my general area that could do it without me sending my PCM off? I have a guy with a Tech 2 But he couldnt do anything.
    99 Grand Prix SE-Blue CAI, 3.03 GR Transmission, U Bend Delete.
    time to call the exterminator
    Reply With Quote  
     

Similar Threads

  1. gear ratio
    By shawnschuldt in forum PCM Tuning
    Replies: 3
    Last Post: 05-02-2011, 08:04 PM
  2. Gear ratio's??
    By reallyfast1 in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 1
    Last Post: 09-10-2010, 10:10 AM
  3. gear ratio
    By gtpinsc in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 2
    Last Post: 09-04-2010, 02:01 PM
  4. Gear Ratio Pro's and Con's
    By dagger in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 12
    Last Post: 10-06-2009, 03:02 PM
  5. what is my differential ratio, and first gear ratio?
    By 2000GTP in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 6
    Last Post: 11-07-2008, 09:31 AM
Tags for this Thread

View Tag Cloud

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •