Results 1 to 12 of 12

Thread: Speedometer fluctuating, bad vss?

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Fuel Injected!
    Join Date
    Dec 2013
    Location
    Middle of Nowhere, MT
    Posts
    107

    Speedometer fluctuating, bad vss?

    My speedometer just started to act up on my 94 Chevy C1500.
    Manual trans, pcm:16197427
    Datalogging with Tunerpro shows the same fluctuating readings that the dash speedometer does.
    Started acting up in the 50 mph range, but now does not want to read anything until about 15mph, then fluctuates at times.
    Checked wiring, and grounds and have not found anything wrong, getting no error codes.
    Does this sound like a bad vss, is there a way to test a vss?
    Hate to just throw money at it and hope, so would like to know more.

    Thanks, any help and insight is appreciated.
    Been searching net, haven't found much yet, my Haynes manual says take to dealer to diagnose. That's not going to happen

  2. #2
    Super Moderator Six_Shooter's Avatar
    Join Date
    Feb 2011
    Posts
    2,968
    Sounds like a VSS going bad to me. Thge only other thing it could be would be the DRAC/VSSB, but I don't think I've ever seen a bad DRAC, unless someone was messing with it.
    The man who says something is impossible, is usually interrupted by the man doing it.

  3. #3
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Loose wire issue?

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  4. #4
    Fuel Injected!
    Join Date
    Dec 2013
    Location
    Middle of Nowhere, MT
    Posts
    107
    Six_Shooter, I am not sure what DRAC/VSSB is, will have to do some research. No one has messed with it.
    EagleMark, if there is a loose wire, I have not found it. Tried to check everything.
    Is there anyway of checking the vss sensor, other than replace it on a hope?

  5. #5
    Fuel Injected!
    Join Date
    Dec 2013
    Location
    Middle of Nowhere, MT
    Posts
    107
    I assume everything runs into the pcm, and signals go from there?
    Meaning, vss goes to pcm, then to speedometer, and cruise control?

  6. #6
    Super Moderator Six_Shooter's Avatar
    Join Date
    Feb 2011
    Posts
    2,968
    No, VSS goes to the DRAC/VSSB then out from there to the PCM, cluster, cruise, etc.
    The man who says something is impossible, is usually interrupted by the man doing it.

Similar Threads

  1. TBI fluctuating mileage?
    By BrandonA. in forum GM EFI Systems
    Replies: 8
    Last Post: 06-15-2014, 09:41 PM
  2. E38 Computer ~ EFI Live Speedometer Calibration?
    By dave w in forum OBDII Tuning
    Replies: 11
    Last Post: 05-15-2014, 02:45 PM
  3. Speedometer Calibration for 1995 Z28
    By 95Lt1 in forum GM EFI Systems
    Replies: 3
    Last Post: 01-02-2014, 07:23 AM
  4. Fluctuating TBI fuel pressure???
    By devind in forum GM EFI Systems
    Replies: 4
    Last Post: 04-09-2013, 05:41 PM
  5. GPS Speedometer for laptop?
    By EagleMark in forum Gear Heads
    Replies: 24
    Last Post: 12-23-2012, 03:32 PM

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
  •