Speedometer && ABS Problems..

[HicktownGirl94]

Okay, so I got my exhaust done last Friday on my truck Exciting righhhttt? Alrght, yes it was. But as soon as I got my truck back my Speedometer started freakin' out in first and second gear and my ABS light is constantly on. Whyyyyy.. my speedometer will work after my truck shifts into second. but it will still freak out at times and bounce all over the place. it also seems to be shift hard and late. like 3500 rpm..
HELP

 

[Skandocious]

Sounds like your VSS has gone postal. If you've got a gen 9 truck then the vehicle speed sensor is located on top of the rear diff. You can try removing and cleaning it-- it's a magnet that picks up signals from the toothed ring attached to your ring gear.

What year is your truck?

Edit: just checked your gallery-- looks like a gen 9. Check that vss.

 

[nobodyspecial]

Or the ABS module died. It should be behind the glove box. Unplug it and see if things work. Thats what I had to do to mine. The module went to crap, but the signal passes through it. With the module unplugged, the signal gets through but doesnt get all jacked up. This will disable the rear abs.

 

[HicktownGirl94]

My truck is a 1994 to answer your question.

 

[HicktownGirl94]

Thank y'all so much I will definitely try this. I hate havin my truck act funny and I am super excited about my exhaust and would love my truck to function properly.
Do y'all know what would have caused this??

 

[john112deere]

Being that the VSS sits on top of the rear axle, and the problem started right after you had exhaust work done, I'd be taking a long hard look at the wiring to make sure they didn't damage or disconnect anything while they were working....

But, VSS failure isn't uncommon on those trucks, so it could just be a fluke, too.

 

[HicktownGirl94]

I will be sure to look.
Did this get caused by maybe the plasma cutter or...? I guess I am not very informed on this topic sorry :[

 

[john112deere]

I will be sure to look.
Did this get caused by maybe the plasma cutter or...? I guess I am not very informed on this topic sorry :[

Basically, I see two possibilities: the sensor just happened to fail (and, realistically, for that part on that truck, the question of "why" is not worth looking into...call it "normal wear", I guess), or the exhaust shop screwed it up somehow.

If that's the case, and without having been there, or seeing it, it's anybody's guess what they might have done. The most-likely choices I see are:

-they accidentally cut or pinched a wire while they were working
-they disconnected the wiring to move it out of their way to avoid the above, but forgot to reconnect it when they were done (hope for this one- it's an easy fix)
-the new exhaust routing is such that heat from the pipes melted some insulation and shorted the wiring out (this seems unlikely to me)


For a first step...crawl under the truck, and find the sensor sitting on top of the rear pumpkin, then trace the wires...they probably run up the driver's side frame rail (wrapped in wiring loom) to the front of the cab, but I'm not sure. See if you see anything obviously wrong.

 

[HicktownGirl94]

okay, thank you so much

 

[A_G]

The vss is like 35.00 bucks btw and theres a very good chance when you go to wiggle it out of the diff. Its going to break. (all the ones ive done have) you can try cleaning it up. But id just replace it if it was me.

I do know when a vss goes out you should have this
Check engine light on
Brake light (and or parking break set light if you have it)
and speedo either not functioning or acting wierd, like only work above a certain speed or below a certain speed, jumpy, bouncy watever...

 

[HicktownGirl94]

Thank You Guys SOOO Much for your help! The VSS was what was wrong with my truck! You guys are so much help! Thank y'all soooo much!

 

[Truckin4life]

Any time.