Page 2 of 2 FirstFirst 12
Results 11 to 14 of 14

Thread: auto transmission won't shift and rpm& speed guages don't work

  1. #11
    Full Member smokejumper0902's Avatar
    Join Date
    Dec 2005
    I just had this same problem, it is the trans cpu module. The part is around $150.00.

  2. #12
    Full Member
    Join Date
    Jan 2006
    Lebanon, OR
    Quote Originally Posted by gmcer
    The two guages and the transmission not shifting by itself both stopped working at same time. I bought a new transmission three years ago never had any problems with it. I took truck into a good place to have it checked and was told its not the transmission but probably something to do with something in the electronics. He hooked up a computer to my truck just to see if it was reading a rpm signal. It did. It just was not reaching my my rpm gauge. So somehow the 2 gauges not working and the auto transmission not shifting are somehow connected somewhere I guess. I can still drive the truck but I have to manually shift from second to third to start or I just leave it in third. First gear and Drive don't work right now either. My wife was driving one time and she said the gauges all of a sudden started working for just a min and the truck auto shifted fine before it went back to not working. Does anyone know what is causing this? I've heard it could be the computer itself or something called a vulcan module ( i think that what it was called). Any ideas and if it is that module is it a fairly cheap item and where is it located?
    My truck is a 1995 gmc sierra 350 5.7L 4x4 1500

    Also I broke the door handle. where can I buy or do I have to go to dealer?
    Friend with the same year truck has gone through 3 tranny's just driving....
    1984 Ford F150
    2003 Ford F350 King Ranch
    2005 Toyota Tacoma SR5
    2002 Yamaha YZ125
    On a quiet night you can hear the chevys rusting...

  3. #13
    Full Member
    Join Date
    Feb 2006
    Cullman, AL


    have a '99 GMC Z71 w/ 200K miles. was out putting out some political campaign signs and tranny started shifting really hard, thought it would jump out the chasis. did it several times, then stopped for gas, restarted and drove off like nothing had ever happened! stopped at dealership and they said that if there was no message on the trouble screen in the dash then there was no reason to check for any codes? days later stopped for coffee and when I tried to pull off truck would barely move. stopped, shut it down, waited ~30 sec. and restarted engine and then pulled off like nothing ever happened.
    someone mentioned a "cpu" what and where is it??

  4. #14
    Senior Member mrjohnwayne's Avatar
    Join Date
    Apr 2005
    Sounds more like shift solenoids
    John Wayne

    2000 F-350 7.3L Powerstroke 4x4

Page 2 of 2 FirstFirst 12

Posting Permissions

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