Whip

I hadn't even thought about how it might affect the warrenty on the rest of the power train. I don't think I'd want to take a chance on voiding that. At this point I've started shopping for a different truck. It won't be a GM. If we start seeing many reports of trucks going into limp mode and sitting waiting for parts that don't exist, I wonder what that will do to the used GM truck market. Thinking I might not wait around to find out.

Are you thinking about installing yourself? It's probably more than I woukd want to tackle, but my wrenching skills are limited. I also wonder how it would cause any conflict with GMs software "fix", and what would happen if it ever threw a code for the transmission control valve. I'm sure you'd be on your own at that point.

I had forgotten about this post from last spring and thought I would post a follow-up for anyone who might come across it. My trailer brake issue turned out to be a problem with a worn wire inside the axle on the trailer, and nothing to do with the truck itself. Intermittent wiring problems are so tough to diagnose and track down, so we were trying as many different things as we could come up with. Wish we had guessed right in the first place, but happy to have finally figured it out.

I posted this reply to a diiferent thread, but am reposting it here hoping that more might see it. I just had my truck in for the recall addressing the rear wheel lock up issue yesterday. I'm very disappointed in the "solution" that GM came up with to address it. All it amounts to is a software update that will monitor wear on the valve body. When it detects that you are within 10,000 miles of a potential failure it will immediately throw the truck into Limp mode and limit you to a max of 5th gear. They have no intention of replacing any parts or doing a real fix until you actually have that happen. I'm headed to AZ next month - 1,500 miles from home. 5th gear item going to get me and an 8,000# trailer back home. Dealer said that these valve bodies can take months to get on back order. So am I supposed to just roll the dice and hope it doesn't happen? I can't sit 1,500 miles from home waiting on a part. I have zero confidence in this truck to take it on any long trips. And GM apparently has no plan to change anything in the future until i might actually be limited to 5th gear, so all future trips will come with the same fear. All this recall does is cover GM from liability. It does not fix the problem. They are going to let the owners sit wherever they happen to be at the time a potential failure is detected. They absolutely need to reengineer the part that can cause the failure and replace it. Or at a bare minimum at least give us a warning 5,000 miles before throwing it into Limp mode and effectively disabling the truck wherever it happens to be.

I just had mine in for this recall yesterday. I'm very disappointed in the "solution" that GM came up with to address it. All it amounts to is a software update that will monitor wear on the valve body. When it detects that you are within 10,000 miles of a potential failure it will immediately throw the truck into Limp mode and limit you to a max of 5th gear. They have no intention of replacing any parts or doing a real fix until you actually have that happen. I'm headed to AZ next month - 1,500 miles from home. 5th gear item going to get me and an 8,000# trailer back home. Dealer said that these valve bodies can take months to get on back order. So am I supposed to just roll the dice and hope it doesn't happen? I can't sit 1,500 miles from home waiting on a part. I have zero confidence in this truck to take it on any long trips. All this recall does is cover GM from liability. It does not fix the problem. They are going to let the owners sit wherever they happen to be at the time a potential failure is detected. They absolutely need to reengineer the part that can cause the failure and replace it. Or at a bare minimum at least give us a warning 5,000 miles before throwing it into Limp mode and effectively disabling the truck wherever it happens to be.

I am still struggling trying to diagnose a problem with my trailer brake controller. My post is long, but I'm hoping someone with more knowledge than me might be able to deduce what is going on. I have read about the issues with 2024 trucks when connected to a trailer with solar. That sure sounds similar to what I've been experiencing, but doesn't seem like it applies to older trucks. So I'm starting this thread from scratch. Very sporadically while towing an RV I get the message "Check trailer wiring" followed immediately by "Trailer brakes connected". Sometimes it doesn't happen for a copulation hundred miles, and then will happen repeatedly ten times in a row before stopping again. Twice I've gotten a message saying "Service trailer brake system". When this battlements I lose the trailer brakes entirely and find that the fuse for the trailer brakes is blown. I replace the fuse and everything works again for awhile. I towed a different trailer that did not have trailer brakes and with that one I got the "Check trailer wiring" message and found that I had lost the rear running lights and side marker lights. After unplugging, reconnecting and restarting the truck they were back on. I have replaced the trailer brake controller located above the spare tire and also the trailer connector plug in on the truck. My truck is a 2021 GMC Sierra 2500 HD. I'm at a loss on what to try next or how to diagnose this. Any help is appreciated!