1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

trans issue

Discussion in 'Chevy Trucks' started by gman2310, Jan 24, 2012.

  1. gman2310

    gman2310 Senior Member
    Messages: 171

    Guy that plows for me has 02 chevy 2500 gasser. His truck is throwing a t0300 code. While driving around town the truck is fine, shifts normal. If he takes it on the parkway and gets up to 70-75, it will pop out of overdrive and then throw the check engine code. Its almost as if the torque is unlocking or coming out of lock up. Hes changed most of the sensors already. Any suggestions
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    T0300? A typo perhaps as there is no T series codes. Probably referring to a P0300 which is random misfires, which if sever enough will cause the PCM to release the TCC...sometimes rather abruptly. Sounds like he's already thrown allot of parts at it. Probably could have fixed it by now and with less expense if the correct diagnostics would have been done first.

    Need to find out why it's misfiring by starting with the basics. Live fuel pressure check, data checking via scanner checking EGR and MAF data, and misfire counts especially to see what you're working with and then do a CKP re-learn. Which is a periodic good idea on the 6.0's anyway.
  3. lawnmedic

    lawnmedic Senior Member
    Messages: 703

    My P0300 code problem was fixed with a crank sensor relearn.
  4. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Yes we covered that too in a rather lengthy thread a while back as well and I think I mentioned there that I often do a CKP re-learn as PM on the 6.0's it's so common. Probably wouldn't take too much searching for it to pop up.

    However not knowing any history or even real details on the vehicle I wouldn't make it a primary recommendation.