Tachometer/Speedometer...and a few other things

I have a 96' Aurora. When I bought the car, the tachometer did not work properly (it just goes where ever it wants.) I just figured that it was a fluke and did not worry about it. Lately, the speedometer has been doing the same thing; however, the weird thing is that as soon as it starts acting up, the Traction Off light comes on and then the DIS starts displaying all sorts of messages. It usually starts with "Service Vehicle Soon". When that message pops up, the temperature gauge goes down to zero. The DIS also displays "PASSKEY SYS FAULT", "CHECK AIRBAG", "OIL LEVEL SYS FAULT", DATE NOT AVALIABLE." I find it very hard to believe that all this could go wrong at once. Could this be a chip of some sort? Another thing about the Traction Off light, it usually comes on if I leave my car idling for about ten minutes. It also comes on after traveling for about an hour regardless of speed.

Sounds like you just have a computer problem. I would find a competent local shop with good diagnostic capabilities and have them do a work up on it. $60-$100, and usually they won't charge at all if you allow them to do the work, only if you pull the car out for DIY.

Thanks for the help. I will let you know the verdict.

Hi. I have the same problems with my 95. See Crazy Control Panel thread. Did you ever resolve your problem? If so, how?

GOT IT FIXED FINALLY! It was my instrument control panel cluster (ICP); In addition, my alternator was bad as well. Everything works perfectly now.

GOT IT FIXED FINALLY! It was my instrument control panel cluster (ICP); In addition, my alternator was bad as well. Everything works perfectly now.


I have a 1997 Aurora and it is doing the exact same thing. On my car I noticed that when the tachometer and speedometer begin acting up that the batter voltage on the DIC is less than 14.4 volts. The problem gets worse as the voltage approaches 12.5. Did you notice this when your car was acting up? Also, did replacing the ICP work long term?

My problem with the tach and speedometer coincided with a transmission and ECM replacement. My ICP and alternator checked out OK. After a while I could see that the tach and speedometer went most wacky when I turned up the air conditioning fan. It took a lot of detective work, but extra ground wires finally solved the problem.

Thanks. I am going to try adding a few ground wires.

Yes, I also had a bad ground. It caused my tach to do the same thing again. Hopefully now it is all fixed. This is the only major problem that I have had with the car....can't complain too much it now has 175,000 miles on it.

Yes, I also had a bad ground. It caused my tach to do the same thing again. Hopefully now it is all fixed. This is the only major problem that I have had with the car....can't complain too much it now has 175,000 miles on it.


Did the mechanic tell you where the bad ground was located? Any information you could provide would be greatly appreciated.

Thanks,

Michael

sounds like i have the same problem with the possessed instrument panel did your drivers control panel go crazy too? the cluster is very expensive, any suggestions thanks !

sounds like i have the same problem with the possessed instrument panel did your drivers control panel go crazy too? the cluster is very expensive, any suggestions thanks !

In my case there was nothing wrong with the instrument cluster & I did not have to replace it. The culprit was a bad ground on the passenger side of the engine compartment directly in front of the tire. There is a little black fuse box where the ground is located. I loosened the ground and cleaned the contact point on the frame. I also purchased a short piece of ground wire from the auto parts store and added another ground to the strut tower bolt. The problem went away with very little investment.