Prostar axle scale not reading weight

Discussion in 'International Forum' started by SemperFiServices, Apr 7, 2020.

  1. SemperFiServices

    SemperFiServices Medium Load Member

    371
    213
    Jan 29, 2013
    Indianapolis, IN
    0
    2015 Prostar, the digital in cab scale used to be within 300lbs of actual weight on the drives, but now it's stuck reading 500 lbs, loaded or empty. I did recently replace the leveling valve, but that shouldn't have anything to do with it. I haven't tried disconnecting the batteries for 20 min to reset the system, but I don't know if that'd work either. Where exactly is the sensor at so I can verify it's condition? Thanks for any help y'all can offer!
     
  2. Heavyd

    Heavyd Road Train Member

    6,867
    4,810
    Feb 4, 2009
    0
    Air bag pressure sensor is plumbed into usually the left rear rear air bag. Sometimes there are two sensors there, one for advanced abs and one for load sensing. Same sensor, you can switch them to see if the sensor or wiring is faulty.
     
    SemperFiServices and QUALITYTRUCK Thank this.
  3. SemperFiServices

    SemperFiServices Medium Load Member

    371
    213
    Jan 29, 2013
    Indianapolis, IN
    0
    Heavy, thank you for your reply. I actually found them this weekend just looking over the truck. I didn't know why there were 2 sensors on the bag, now I know what the second one is, but not what air bag pressure has to do with abs? I disconnected them both, fired up the truck, and once again had a good air bag reading, but the next day it was back to being broken. Didn't see any corrosion in the pins, could the sensor just be bad after 500+k miles?
     
  4. SemperFiServices

    SemperFiServices Medium Load Member

    371
    213
    Jan 29, 2013
    Indianapolis, IN
    0
    Ok, I swapped connectors in both sensors, no change. So I got the Prostar wiring diagram online. Found out that there is a 5 volt input to the sensor, checked both sensors with my multimeter, found one has 4.8v, the other only about 2.3v. I still need to verify, but I'm assuming that the abs sensor is also at 5v, so that means there's a bad wire or connection somewhere. If that's the case, instead id tearing apart the wiring loom, I might just add a jumper wire from the other connector that has a good 5v to the other one, and then I should be good to go.
     
  5. Heavyd

    Heavyd Road Train Member

    6,867
    4,810
    Feb 4, 2009
    0
    Yes, you can do that. 5 volt reference is the same for each.
     
  6. SemperFiServices

    SemperFiServices Medium Load Member

    371
    213
    Jan 29, 2013
    Indianapolis, IN
    0
    Sorry for late reply, yeah I jumped the wires and all is well
     
  7. Heavyd

    Heavyd Road Train Member

    6,867
    4,810
    Feb 4, 2009
    0
  • Draft saved Draft deleted