Congrats. on your web page!
I have a 2001 Jeep Cherokee that while I am driving it, the speedometer and tachometer gauges drop to the bottom, and come back again after a while. This keeps going on and off. I am getting a display on the tripometer………. NO BUS. but nothing seems to affect the performance because it still runs well.
I had it analyzed by Auto Zone and they came up with the code P0455.
It states………..Evaporative system large leak detected
1) defective, loose or missing fuel cap…..REPLACED
2) Evap. canister broke, hose cracked or not connected
3) Purge or vent solenoid defective
4) Vacuum leak at engine.
The car has 101K and I can not afford to invest too much $$$ because I intend to sell it at the end of the year, but I will like to solve the problem (hopefully not major) so the next guy won’t be stuck with a major problem. Could you tell me what would be almost the sure shot to repair it the least expensive way?
Interesting…if the engine performance is not affected during this drop I would suspect a problem with the PCM – power control computer (the computer) or the instrument panel itself.
There is not really much in between…the computer gets a signal from the engine, sends that signal to the instrument cluster. If the signal from the engine was wrong, I would expect the engine to run bad or not at all…since 0 RPM would mean the engine has stopped running.
BUT, since your engine runs fine, I can only assume the computer is getting proper data, it is just not sending proper data to the instrument cluster or the cluster is not interpreting the data from the computer correctly. Since both items are expensive to guess at.
I would have a mechanic look into this further. Both of these items, computer and cluster can be purchased used at a junk yard though to help offset costs.
Keep me posted will ya?
Reader Follow Up
Good morning Austin,
One more thing,do the message displayed on the tripometer NO BUS and the codes obtained from Auto Zone narrow down the suspected problem and your diagnosis? (you forgot to mention if that was a factor or not)
I was planning to go to a junk yard this weekend…will keep you posted on the outcome so we can share it with the rest of us!!
Have a wonderful day……..
I think the code that Autozone found was probably just an old code stored in memory; I don’t think that is related at all. The error message….honestly, I am not real sure what is causing that I can only assume that the loss of computer signal or a problem with the control head is the culprit.
Again, I would suggest you spend $75-100 for a dealership mechanic to diagnose the problem for you so you can correctly repair the problem yourself.