I purchased my 2004 Monte Carlo SS new back in 2004 and it has had a strange anomaly since day 1. Yes, I took it in while it was under warranty quite a few times and they could not duplicate the issue. After the third time I demanded they change the instrument cluster, which they did but the issue still continued and still does to this day, yes I continued to take it back to different dealers but no one could figure it out and I was wondering if anything else has experienced this

I'll be driving along and the dash cluster would do what appears ti be a self check or reset. ALL lights flash, ALL gauges go to the bottom and back to the top basically the same way they do when you start the car then everything returns to normal. There is no rhyme of reason or pattern when it does it. It has done it at night, during the day, breaking, coasting, while the cruise is set, during summer,during winter. The car does NOT shut off, the cruise control does not stop working, everything else is completely normal, other than the "Self Test" By the way it does not do it all the time, sometimes it does not happen for months. The most times it has done it was once when we were driving to Phoenix from California and it did it 4 times on that trip. Like I said, no rhyme or reason

My wife calls it her ghost but I believe there has to be a reason.

 

That same behavior can happen if the cluster looses power or ground and then gets it back again. Definitely weird that it has been a day 1 problem. If it truly lost power, in theory, the car should store a code for the issue (I have seen the code when I start the car with no cluster plugged in, does not cause a active service light, but the GM Tech 2 can tell you the code occurred, I believe it starts with a U).

Odd for sure!

 

If this was something that just stated "out of the blue", I would tell you to start tracing ground wires. Most likely a corroded or loose wire. But since this has been doing this since new, and even after the cluster being replaced, I am at a loss of what is going on, especially since it has not changed over the years.

 

Any solution to this?
I’ve seen it a few times where the female IPC connector fits the IPC pins just loose enough that it can drop connection for a split second under the right circumstances.
Pull the IPC out and use a fine pick and either slightly close up the female or put all the male pins on the IPC on a slight angle. There was a TSB years ago about intermittent connections causing “phantom cluster” issues. I don’t remember the TSB number, and have no access to find it again. Sorry.

 

I have a 2000 Monte . Not the same issue, but on the instrument cluster, the information box that contains the odometer and "P R N D L2 L1" went dark. I brought it to the dealer. They said all the instruments were on a single circuit board, and I'd need a new (rebuilt) cluster. The rebuilt cluster alone was $850. Got the car back today. I have an issue I didn't realize when I left the dealer: the ignition switch is in the center of a square panel. The panel is loose on the dash. I can peel it away at the corners. Does anyone know how this secures to the dash? I'm guessing I'll have to schlep it back to the dealer!

 

Have your stepper motors ever been replaced? The gen 6's as well as same year Impalas and some others have faulty stepper motors. I have no idea if that is what is causing your problem, but mine used to give me random readings at random times -- it would say I was going 85 when I was going 30, for example. The motors are dirt cheap -- you can get the kit for all the motors and new bulbs for about $20. If you can solder, you can replace them yourself. if you don't, you can send out the panel and some companies will do the works for about $150. I could only find one shop in my area that knew what I was talking about. I supplied the parts and they did all the work (total cost to me about $120.)

PS, The Chevy dealership wanted me to buy an entire new instrument panel for about $500.

 

actually, yours doesn't sound like the same issue as mine, now that I reread (sleep-depraved here)

 

Thanks for the info. The dealer already installed a rebuilt cluster. $850, plus labor and tax