12v cummins overdrive issue ?

i have a 95 ram 2500 4x4 auto 12v and my truck doesnt go into overdrive after changing transmission fluid i tried again and it caught O.D for a split second and shifted out and hasnt gone back in ever since. was wondering if someone could help me ?

4 Answers

Relevance
  • Anonymous
    1 month ago

    I like the T.P.S. answer but since this happened right after you changed the fluid I'd have to say check that first. Is it at the full mark when warm and on level ground, running in park?

  • Snezzy
    Lv 7
    1 month ago

    On my 92 and 93 Cummins trucks there is a "throttle position sensor" that needs fiddly adjustment for the OD to kick in properly. Mine was at 0.98 volts and a few days ago I changed it to 1.01 volts (by using an 11-mm wrench where the book says to use a 10-mm one) and it worked a lot better. The book specifies, IIRC, that between 1.00 and 1.25 is appropriate, but Jim Jessup (founder of "Diesel Tune-up" N. Vernon, Indiana) says it should be 1.00 exactly.

    Some people simply replace the entire TPS with a resistor network with a pot and maybe a dash-mounted voltmeter to allow hand setting of the critical voltage.

  • 1 month ago

    You need a mechanics scan tool to pull any tranny codes and to read the transmission data to diagnose this problem.

  • Anonymous
    1 month ago

    Yeah, buy a Cummins Titan. It could be a temperature sensor. It could be a lot of things. Get a computer read out.

Still have questions? Get your answers by asking now.