grand cherokee speed sensor

jonnyB

jonnyB

Well-Known Member
Joined
Nov 15, 2006
Location
rockwell, NC
my speedometer in my zj goes crazy sometimes, i would think it is the speed sensor goin bad, but is there anything else it could possibly be? just wanna make sure b4 i start spendin money. thanks
 
its a 96, and by crazy i mean bouncin around every now and then, it moves from 0 to 80 sometimes in less than a second. and sometimes it does it when im not moving at all.

what other things could it be?
 
thanks, its a 4wd, i guess ima just buy a new speed sensor, i just wanted some opinions b4 i spent the money
 
A bouncing speedometer sounds like a speeometer cable going bad. Is this an older ZJ? I don't know if it has a speedo cable or not. Newer vehicles don't have them to the best of my knowledge.

For the VSS -

Make sure the wiring harness has a good connection. Clean out any caked up mud or grime if necessary.

You could pull the gear and inspect it. I don't know why they don't use a metal gear.....

Be sure it's "clocked" correctly.

A 96 or newer vehicle should throw a code if the VSS was out of whack. I reinstalled mine after pulling the XFer case and didn't have it clocked correctly. The speedo didn't work at all and threw a code.
 
No speedo cable on ZJ's. It's electronic.

He shouldn't have to worry about it being clocked right, he didn't take it out at all.

Maybe it cracked the speedo gear for some very odd reason, but if that happened I have a few stock ones at the house.
 
It could be a grounding problem, i have seen a few problems behind the dash. It could also be the instrument cluster.

Does the transmission act weird? Miss shifts or slip?

Speed sensors are easy to check if you have a scope.
 
actually the tranny has slipped and miss shifted only a handfull of times in the past 6 months. and twice in those 6 months the lights in the dash blinked a few times then were fine. all that stuff happened at very random times, as well as the speedo problem. but the speedo wasnt acting up when the lights were flickering. sound more like a ground problem?
 
rollota said:
its a 96, and by crazy i mean bouncin around every now and then, it moves from 0 to 80 sometimes in less than a second. and sometimes it does it when im not moving at all.
what other things could it be?
Click to expand...



actually, it's a '97. lol

I've got a video or two here on my computer of it from when I had it.
 
Back
Top