Electrical issue?

[jared4832]

My Bonneville has had a strange issue that I haven't been able to figure out, it's been inconsistently occurring since the end of summer, today it was the worst it's been.

When I start the car, these things happen:
The RPM and Speedometer stay stuck on 0
The Odometer doesn't register miles (even if car is in motion)
The electronic "Driver's Information Center" messages are all frozen and I can't switch messages
The "Calibrate Compass" message sometimes appears
My cruise control and turn signals don't work (but the 4-way hazards and brights work)
All these things happen at the same time. While this problem happens:
My HUD works properly
Boost and oil pressure gauges work properly

But this problem doesn't occur every time I start the car, and the strangest part is that if the car stays running long enough, everything seems to correct itself. Also strange is that it only happens in cold weather. These problems never occur in the summer. It's as though "the car needs to warm up" before everything starts to work. Usually it only takes 5-10 minutes for everything to start functioning normally.

I have not been able to figure it out, I hope someone can help me out!

[bobgto65]

This one may not be easy to solve because it is intermittent but that likely means a bad connection or ground. I would remove and reseat all the connectors to the PCM a few times to clean them up, check the PCM ground connector below the ignition module and check the instrument panel ground connection on the body below the dash on the cowl just in front of the passenger and drivers door. You have to remove the plastic trim to see them. Make sure that are all clean and making good connections. If the problem persists, try removing the instrument panel cluster and reseat it a couple times to clean the connectors on both ends of the cluster as well.
If none of the works you can also scan the car to see if there are any stored trouble codes. Lastly, your PCM may be going bad.

[jared4832]

Just in case this problem ever happens to anybody that may Google search it or come across it on this forum, I got this problem fixed over Christmas break.

It was simply the ignition switch.

It took a Buick/GMC dealership three hours to figure out that it was only the ignition switch. It was such a hard problem to describe to the mechanics that I thought for sure they weren't going to find the culprit behind this issue. I was close to telling the dealership to stop working on it as they weren't finding anything and I didn't want the labor bill to keep piling-up. But finally they realized that the problem was likely the ignition switch, which made sense as it always seemed to me that even though the car was started, it was almost as if the car wasn't realizing that it was started...

Haven't had any issues since, thankfully. If you read my initial description of the problem above, you should be able to tell that it wasn't a fun issue to have!