Results 1 to 3 of 3

Thread: vcm not displaying rpm?

  1. #1
    Potential Tuner
    Join Date
    Mar 2021
    Posts
    6

    vcm not displaying rpm?

    I have a 97 2.5l tj se manual trans and the vcm scanner wont read rpm at all? I've tried 12engine rpm (angular frequency) and 12engine rpm - high resolution (angular frequency) the latter reads but is an off and on reading so basically drops to zero and then back up to the correct reading which is useless. any ideas of how to get a reading? I have tried changing polling intervals but this just slows down the reading and does nothing to help with getting it to read correctly.

  2. #2
    Tuner in Training
    Join Date
    Apr 2021
    Location
    SE Tennessee
    Posts
    16
    Quote Originally Posted by beserkr View Post
    I have a 97 2.5l tj se manual trans and the vcm scanner wont read rpm at all? I've tried 12engine rpm (angular frequency) and 12engine rpm - high resolution (angular frequency) the latter reads but is an off and on reading so basically drops to zero and then back up to the correct reading which is useless. any ideas of how to get a reading? I have tried changing polling intervals but this just slows down the reading and does nothing to help with getting it to read correctly.

  3. #3
    Tuner in Training
    Join Date
    Apr 2021
    Location
    SE Tennessee
    Posts
    16
    Having same type issues w/ 2020 Challenger. The only RPM PID that I can rely on is the one identified as (SAE). The green hi-lited RPM does not work every time. There are several RPM PIDs for me to select from but most don't work at all. Not getting a lot of help out of this Forum are you?