wacnstac

I'm hoping it wouldn't even know the switch is unplugged.

Dealership was of zero use in debugging this problem. No codes = no fix. The truck has now tried to put itself into terrrain mode randomly. This mode is not even available on this truck as the truck has 4WD Low! and there is no separate switch for terrain mode or an option for this in the menu. I'm thinking this definitely has to be an intermittent mode selector switch. I think the way to narrow this down would be to remove the switch from the harness. I am under the impression, that I could drive the truck this way knowing that I would not be able to change the modes obviously.

I had changed the battery to a non-OEM but AGM battery two winters ago. Now I'm paranoid that the change may have caused some of these problems. Dealership was focused on a bad Transfer Case Control Module and I am not convinced. The TCCM but I don't think the TCCM is involved in trailer tow mode or the different sport modes which the vehicle likes to switch between on its own. I told them if they don't find anything wrong with the switch on the dash, or the harness to it and verify the BCM and TCCM software versions, and a CAN bus ground inspection, I just want the vehicle back.

Thanks for the great response. Dealership claims they tried another drive mode selector switch on the dash and the same problem occurred. I know that a 4LO switch is prevented when moving but having that come up at highway speed is very disturbing. They said there are some codes present but of course they didn't tell me what they are. When the vehicle does change modes on its own, it always obeys what I do afterward with the dash mode selector switch at least for a while.

Any idea what the TSB number is? Dealer doesn't seem to be aware of any of this.

I have a 2020 Silverado Trail Boss which switches to trailer towing mode, all the different driving modes, 4wd high and low all by itself while driving down the road. I can typically switch it out of these modes and back to normal by the switch on the dash. Last straw was when it started trying to switch itself to 4wd low while at highway speed. It didn't happen but was scary enough to take it in. Dealership seems stumped. They are talking about "rear actuator or rear carrier" and neither one of those make any sense to me. Seems like they would be talking about a transfer case module or transmission module. I'm concerned they are on the wrong track since all of these things are controlled by the switch on the dash, logic would say it was the switch or wiring to the switch. They claim they have swapped in a different dash switch and the problem still happens. Searching the internet doesn't yield a lot of info on a problem like this.

The harness at the connector where the brake pad life sensor plugs in got shreaded by whoever rotated by tires or did the brakes. I had a new hardness. Can't figure out where the end furthest away from the brake pad plugs into vehicle. Does anyone have a service manual or a picture of where that is? Must be on the engine side of the wheel well somewhere? If it is that buried, I might just splice the harness.

Do I have to take the wheels off to do this, or can I inspect from underneath?

And probably charge me more while they are at it.

Just got my brakes done on all 4 wheels less than six month or go ago including rotors and new brake pad life sensors. Brakes feel and work fine. Just recently I started getting this intermittently. Notice the ---% on the fronts. After a while driving it was toggling back to 97%. Anyone else ever see this?

Unfortunately the dealer has to call Ally for approval and give Ally a diagnosis and estimated time to fix in order for a rental to be covered. GM dealers sell the Ally warranty. I don't believe I can work with Ally directly.

I have already been in contact with social media at GM. The dealer just called, they seem to have diagnosed 3 problems all of a sudden after two full weeks. They still say they need to talk to Ally about approving the repairs. Not sure these extended warrantys are worth the paper they are written on. I bought the Major package which covers everything including a week's worth of rental which I just had to extend. Ally won't pay for rental until there is a diagnosis. Read the fine print before you buy!

Unbelievable, today is the beginning of week 3 with this GM dealership and I still haven't gotten a call about a diagnosis much less how long a fix will take Never seen anything like this.

Well I took my 2020 Trail Boss in for what I suspect is the DFM shudder/lifter problem when just tipping into the gas at speed. That was two weeks ago. They said mechanic could reproduce (good news I thought). Also I thought I did good by buying the Ally major warranty. I bought up to 100,000 miles. I'm at 77,000. Let me warn you about the rental car coverage with Ally. They won't cover anything until there is a diagnosis. Dealer has found a few transmission codes and asked me to authorize 8 hours of work to drop the tranny and investigate a harness. They say this is not yet a diagnosis so no rental car coverage. So what the heck? They can take months to get a diagnosis and you get no car? Major fine print there. All this while the dealer has not worked on either of the other two warranty complaints that I have nor have they done the fluid changes that I asked for. I have also contacted social media at GM and they have been of no real help to date. Worst service experience of my life and I have had many, and it's not even close to being over yet.

Overall I've been pretty happy with Cerakote trim refinisher. There are a few spots that I would like to touch up. Can I reapply over old Cerakote or do I have to remove all and start over? Also there is one area with bumpy plastic around by tailgate drop button where the Cerakote didn't work out at all. How can I remove without damaging the plastic?