How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Wayne Your Own Question
Wayne, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 9824
Experience:  worked on, Gmc, Macks, Freight liner,Mercedes Benz,,Ford, sterling
Type Your Medium and Heavy Trucks Question Here...
Wayne is online now
A new question is answered every 9 seconds

I have a heavy equipment shop. And i got a 2014 freightliner

This answer was rated:

Hi there my name is***** have a heavy equipment shop. And i got a 2014 freightliner M2106 VIN #EHFP7942 It came in my shop because the speedometer said it was going 75 MPH but was actually going 35 MPH But if i hook up the Diag computer it says on the wheel speed sensors the correct speed. This truck has a top speed of 75 MPH so the ECU won't let it go over that. So first thing i changed was the speed sensor on transmission. No go. So i changed the dash cluster still no go. So i took it to freightliner and had them Diag it and thy said that the turbo was bad so we changed the turbo and recalibrated it. Still no go. So freightliner said try changing the VGT valve thinking maybe that was bad as wall. So we did and calibrated it with computer taking all the steps that the computer said to take Still no go! Please help i dont know where to go from here. My first thought

Hi I'm Wayne

I will help you with this

did you have the ECM checked ??

VSS gives signal to ECM, and the ECM gives signal to the

speed gauge , I suggest to have that checked

I hope this helps you

Customer: replied 2 months ago.
Hey Wayne yes that was my first thought but i sent it to Freightliner to have it looked at and possibly replace it but thy said it was fine and the real problem was the turbo. So i think i will take it to another shop for a second look. I will let you know how it goes thank you for your feed back.


Yes I would take it else where

I did not buy that Turbo story , when reading this

Hi. If this helped you

Please rate my answer 3 or more stars.

That is the only way I get credit for the question

or the money you paid stays at JA and I get nothing for my time.

If you need more info use the REPLY button

Not the Poor/Bad service.


Wayne and other Medium and Heavy Trucks Specialists are ready to help you
Customer: replied 2 months ago.
just an update for you i found the problem with the speedometer gauge. So i did find out that the speed sensor was on the back of the transmission and one on the transfer case.But the real problem was the Hi low range valves on top of the transfer case were plugged in backwards so the ECM thought it was in high range but it was actually in low


Well that is a new one for the books,

Good find