Agreed...be thankful it sounds like a 1-off and an easy fix...get 2 lottery tickets just to be safe!

 

Yesterday I got a text fromOnStar that there was a theft attempt on my C8. The alarm was going off when we got back to the car about 30 seconds later (we had just parked & left the car). Checked & everything was fine. Reset the alarm and walked off. Same thing happened 2 more times. I stood there watching it after I set the alarm the 3rd time. After about 40 seconds alarm would go off again. Weird! I did notice that when we left- the passenger window seemed to glitch a little bit up& down a couple of times. This morning when I went in the garage the passenger window was 1/2 way down and the battery was completely dead. Got inside the car with the metal key- popped the hood to check the battery. (Note to self- DO NOT close the doors when the battery is dead! The window doesn’t move down to miss the trim at the top of the door ) Bought/ installed a new battery. Tried indexing the windows. Still have the same problem. Window goes up & down by itself - which is what was setting off the alarm. Can’t drive the car anywhere unless it’s some place that I don’t have to set the alarm & can leave the windows down. Calling the dealership in the morning.

 

It wouldn't hurt to try the start engine - stop engine - open driver's door - leave door open for more than 90 seconds trick to reset the computers. It's a long shot, but I don't see where you have anything to lose.

 

Battery was already dead. That flushed any cached data for sure.
Sounds like an electrical gremlin to me... sometimes a pain to track down.

 

Adjust mirror in tilted position and store in memory 1 or 2

 

Did you ever get this fixed? I have the same issue.

 

Yep, the Chevy dealer body shop took care of it. They said it was easy to fix.

 

Anyone else have issues with headlights taking in water ? Drivers side is full of moisture . Maybe a recall item ?

some pics

 

Streaks or actual moisture? Maybe post some pics?

 

I had something weird happen to me last week when I was out in my C8 that I'm going to attribute to electrical gremlins. I put the car in Z Mode when sitting on a side road waiting to pull out onto a state highway where the speed limit is 55MPH and because it's in a rural area people run much faster. After I got on the state highway (very fast with Z Mode) I switched back to My Mode. The screen showed the settings all the way to the right for everything. That's not the way I had My Mode set up. When I got home and was parked in my garage I went into settings and was going to fix that problem. When I got to the setup for My Mode it was exactly like I had originally set it up. Hmmmm.......has to be gremlins.

 

Could somebody point me to a source for this information, please? I'd like to find out more.

I looked in the Owner's Manual, but I couldn't find anything about it.

 

On my car when switching off Z mode it always returns to Tour mode. Then I have to manually switch back to my mode.

 

Yes, when turning off Z mode the car will always return to Tour mode (same as pressing the Z button again to turn it off). However, when you switch the car off in Sport, Tour or MyMode the car will start in the same mode next time you start it.

 

I've posted this a few times before but worth another post.

It's not in the owners manual. I found out about it from this video. First, start the car. Shut the car off. Then open the drivers side door for 90 seconds (and you have to have it open for no less than 90 seconds). Close door, start the car and the computer cache has now been reset, hopefully taking care of any electronic gremlins one might be having. Watch the video using the link below at the 1:44:46 mark.

 

I was skeptical about this but I have done it twice for two different problems and it worked both times. It should be in the manual but that would be admitting that the computers need a reset every so often.

 

I have a separate thread for this but feel like it should be logged here. In hopes that some one else has had this issue remedied, or once I do it can help in the future. Since it has already been posted I will try and make it more brief here.

Front right pressure lost from display during drive. Service TPMS light comes on and PTM settings can no longer be activated. The car applies brakes at the slightest turns. Took the car to the dealership was told sensor was bad. They wouldn’t replace it because of aftermarket wheels.

Took car to a wheel and tire shop. They replaced the sensor and sent me on my way stating car would register the new sensor after 20 minutes or so driving. After a 40 minute ride home sensor was still not registered and Service System was still active.

Purchased my own sensor tool recommended by forum. It never really worked only one time did the car beep confirming the front two sensors were registered. At one point I lost all 4. The service TPMS light did seem to be reset. I took the car for a 20 minute drive and the sensor still did not register. I forced the car into a scenario that the traction system would activate and instantly got the service TPMS alert again.

I decided to take the car back to the wheel and tire shop. About halfway there the sensor started working all lights went out and I was able to access PTM modes again. I turned around and went home. Took the car out for a weekend drive and everything seemed to be ok. This weekend after an hour or so the service TPMS alert returned. However to my surprise the new sensor was displaying, and the other three were missing!

I decided to head home. After 20 minutes 2 of the 3 returned but 1 never did come back even after another 20 minute drive. At this point I’m not sure I ever had a sensor problem. I will return to the dealer as soon as I can but from my experience so far with GM it’s not going to go well.

If anyone has any ideas of a direction I can point them it would be great. This could now possibly be the third electrical issue this car has had.

 

Well, you can look at fault domains to rationalize where the fault may lie.
If the problem was with a single TPMS sender in a particular tire, you would think you would always see an issue with that tire and not the others. Here, clearly you are seeing issues with all 4 tires.
To see groups of tires behaving together at the same time leads you to think the issue is with the TPMS sensor on the car side. I could see how GM could say they wouldn't troubleshoot it since all 4 wheels are aftermarket. Easy to point the finger there.

However, why would an issue with the TPMS and tire pressure cause the vehicle to "apply brakes" when making the slightest turns?
Is this because the car is trying to limit your speed to avoid a rolled over tire bead because it thinks the tire pressure is too low?

I hadn't heard that the vehicle would apply braking on its own for that. I know if you are driving and you press the E-brake button, it will aggressively apply brakes until it is able to apply the electronic parking brake.

 

1. Even if you have already disconnected the battery - do it again. Leave it disconnected all night then connect.
2. Take it to another dealer.

 

Just for Sh!tz and grins I'd try the ol' turn the car off, get out and leave the driver's door open for 90 seconds. This resets the 'puter's cache.

 

I read an old post in the C6 or 7 section that was similar. In the end it was something to do with cell phone interference of some kind. The car has an overactive traction system I guess when this system alert is present. Or it is because of a deeper rooted problem, like you mentioned on the cars receiving end. I’ve owned many cars with TPMS lights on and never once has it effected the traction management system. The dealer wouldn’t touch the wheels for fear of damage “aka we don’t want this problem”. The wheels I have can’t be damaged any more than a factory wheel could.

I have not tried this but I have done the reset mentioned below.