Topic: Stupid Jeep

[aw12345]

I would say it has a communication error between the dash, the ecm and possibly the OBD 2 connector. The gauges will sweep like that with a bus error, the newer ones will display that on the odometer though. I would try to unplug the dash and plug it back in

[Mozman68]

We have a club meeting tomorrow...going the swap the ecm with another Jeep and see if that is it.

Thanks for all of the info!!

[Mozman68]

Did a little more on-line research and it seems that it could be a CPS issue as that would affect the bus as well causing my code reader errors, sputtering, voltage drop, whacko speedo.....and I'm over 100,000 miles, so it would seem like it is time for a new one.

Thoughts?

[sharpxmen]

Did a little more on-line research and it seems that it could be a CPS issue as that would affect the bus as well causing my code reader errors, sputtering, voltage drop, whacko speedo.....and I'm over 100,000 miles, so it would seem like it is time for a new one.

Thoughts?

could be, but imo you would get some rough idle or the engine would interrupt while driving or revving if the cps was bad - i still think it's speed sensor related (just thinking if the crank would result in those issues why not the speed sensor too since they are both feeding the ecu) - and also, from what i understand in your video was only doing it when you start moving, so another reason to think it's the speed sender. But who knows, this is just me guessing - hope you make the right decision so you don't spend extra $$$. good luck :)

[Mozman68]

I must be a woman....I'm changing my mind again....

It actually happens when not moving...kids think it's hilarious.

I'm going to pull the dash and clean the connections....logic seems to be ruling in this direction as it is not occurring on a regular basis.  I would think that if the ECM or CPS went bad, it would be bad and causing things to be crazy all of the time.  On the way back from lunch it was fine.....stupid Jeep.

[sharpxmen]

I must be a woman....I'm changing my mind again....

It actually happens when not moving...kids think it's hilarious.

I'm going to pull the dash and clean the connections....logic seems to be ruling in this direction as it is not occurring on a regular basis.  I would think that if the ECM or CPS went bad, it would be bad and causing things to be crazy all of the time.  On the way back from lunch it was fine.....stupid Jeep.

are there any other gauges that go nuts? i could only see the speedo in your vid.
if the cleaning doesn't change anything try to unplug the speed sender (i think someone else suggested that before as well, so sorry for that not trying to take credit for the suggestion) - that would tell you if it is related to the sender if it stops doing it.

[Mozman68]

I tried unplugging it yesterday...can't get the stupid thing apart....and if it was the sender, I'm not sure that would affect the volt meter, would it??

And if that was bad, wouldn't it be bad all of the time and not "fix itself"??

Like Art said, I think, probably just the cluster connection or some plug not set in all the way.  That would make sense...go off-road..hit a bump that lossens it...doesn't work for a week...hit another bump that jars it close enough to the contacts and it works....stupid Jeep...

[aw12345]

In some cases it's moisture on the printed circuit board of the cluster.
Try the connector thing first another thing you could try is to dry the circuit board and spray it lightly with some kind of coating that resists moisture.
We have a fair amount of problems with funky instrument clusters that are ecm driven in International trucks. You could try to pmDoctor D on the Rubicon owners forum he deals a lot with IHC trucks I am sure he knows what bulletin refers to that problem and what coating to use. Another fix is to change the cluster which gets pricey

[sharpxmen]

I tried unplugging it yesterday...can't get the stupid thing apart....and if it was the sender, I'm not sure that would affect the volt meter, would it??

And if that was bad, wouldn't it be bad all of the time and not "fix itself"??

Like Art said, I think, probably just the cluster connection or some plug not set in all the way.  That would make sense...go off-road..hit a bump that lossens it...doesn't work for a week...hit another bump that jars it close enough to the contacts and it works....stupid Jeep...

if there are any other gauges doing the crazy bounce then yes it is unlikely that the speed sensor is the problem - i just went by the vid you posted where i only saw the speedometer going full sweep - in this case (if there are any other gauges doing the dance) the loose/bad connectors makes more sense, don't think the speed sender would have anything to do with the voltmeter.

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[jcsanders79]

Moz.  I'd get someone with a better diagnostic tool to check it for you.  The Autozone ones are great for letting you know you need an O2 sensor but aren't  a great diagnostic tool for complicated electrical gremlins!  I know becasue I am currently battling one!!!  The guys that have the proper diagnostic tool can plug a specific card in for your year and model and get a WHOLE lot more info.  They can test most sensors and really disect the code.  Good luck.

[Mozman68]

So, after fixing itself yet again just over a week ago, the speedo starting going whacko yesterday.

Just spent the past hour pulling out the dash and cleaning the heck out of it. Plugged it back in and....speedo still whacko....grrrrrrrrr......

.....stupid jeep.....

[Bounty Hunter]

Likely at the transfer case end.

[sharpxmen]

Likely at the transfer case end.

x2, still thinking it might be the speed sensor - were you able to unplug that thing yet Moz?

[Mozman68]

nah...thought I'd stuff at the easy part first...and it was nice to get it all cleaned up.

[Mozman68]

hmmmm...someone on Pirate mentioned that the clockspring might be the issue...stupid Jeep....