Table 1 shows one common electrical system related problems of the 2025 GMC Sierra 3500.
| Problem Category | Number of Problems |
|---|---|
| Electrical System problems |
Randomly when the truck is turned on, the turn signals will stop working, no noise, nothing. When this happens, the infotainment system also stops working. It is unsafe to be driving and not knowing if your signals are working or not. This has been happening since the truck was purchased from the dealer.
Weekly you will start the truck and have no audio of any kind. No blinker noises no collision warning noises, no radio, no on star noise. No sound at all and sound will never come back on until you turn truck off and wait 20 mins. GMC says it's a known software issue, but this has been going on since I bought the truck brand new back is April of 2025. I live in a hands free while driving state when it's come to cell phone use and can't even take a call with no audio of any kind. I don't see how GMC can say this isn't a safety issue.
Intermittent loss of trailer brake function. While traveling and towing a RV trailer with electric brakes, receive a dashboard alert that trailer brakes have been disconnected. This has occurred since vehicle was new. Trailer brake system has been inspected and trailer is not the issue. Took truck to GMC dealer. They are well aware of common issue with GMC owners. GMC issued a safety bulletin 6+ months ago to dealers to replace the integrated trailer brake controller (rpo code jl1). Per reports that has not solved the issue. My truck did not fall into that safety bulletin. Customer satisfaction program number n232414840 says, with the brake issues caused by a potential fault in which voltage feedback occurs. This is a dangerous safety issue.