Edwin Grundy

We have a 2024 2500 Sierra that we bought off of the lot. It is a basic work truck with the 6.6L gas engine. It has 8000 miles and is currently in the shop needing a valve body for the transmission. It has been in the shop 3 weeks and the part is on backorder. GM is unable to give information on when the part will be available. At first it was between 7/31 to 8/13. The dealer now says 8/14 to 8/26. The customer service people are nice but have no authority and will not let you speak to upper management. I use the vehicle to tow and the dealer does not have a 2500 loaner. GMC will not authorize the cost to rent an equivalent vehicle. They would only state that their policy would reimburse me less than 50% of the cost and I could send them the bill for further consideration. We have averaged 11.5 - 12 mpg in the city. Highway was 13.5 - 15 mpg. Towing is another story. On a recent trip to pick up a pontoon boat in Florida we averaged 5.7 mpg at 65 miles per hour. It tows reasonably well for a gas engine. The boat and trailer combined weight was around 7800 lbs. If you are considering using the truck for towing be aware that we have had problems with the trailer brake controller. Under normal driving conditions, the truck will randomly display "Trailer wiring fault". During this time that will last from 3 to 60 seconds the trailer has no brakes. Recently with an 11,000 gross weight trailer and load, we were pushed through a red light with the antilock brakes chattering so bad that I thought that the truck was going to shake apart. GM has stated that they do not have a problem with the controller but if you search the internet you will find many articles regarding this. A dealership checked the controller and said that it was OK. I forwarded a few posts from the internet to my service advisor. A few days later when I called to check on the transmission part, he stated that they checked the controller and found a fault and that they were going to replace it.

We have a 2024 2500 Sierra that we bought off of the lot. It is a basic work truck with the 6.6L gas engine. It has 8000 miles and is currently in the shop needing a valve body for the transmission. It has been in the shop 3 weeks and the part is on backorder. GM is unable to give information on when the part will be available. At first it was between 7/31 to 8/13. The dealer now says 8/14 to 8/26. The customer service people are nice but have no authority and will not let you speak to upper management. I use the vehicle to tow and the dealer does not have a 2500 loaner. GMC will not authorize the cost to rent an equivalent vehicle. They would only state that their policy would reimburse me less than 50% of the cost and I could send them the bill for further consideration. We have averaged 11.5 - 12 mpg in the city. Highway was 13.5 - 15 mpg. Towing is another story. On a recent trip to pick up a pontoon boat in Florida we averaged 5.7 mpg at 65 miles per hour. It tows reasonably well for a gas engine. The boat and trailer combined weight was around 7800 lbs. If you are considering using the truck for towing be aware that we have had problems with the trailer brake controller. Under normal driving conditions, the truck will randomly display "Trailer wiring fault". During this time that will last from 3 to 60 seconds the trailer has no brakes. Recently with an 11,000 gross weight trailer and load, we were pushed through a red light with the antilock brakes chattering so bad that I thought that the truck was going to shake apart. GM has stated that they do not have a problem with the controller but if you search the internet you will find many articles regarding this. A dealership checked the controller and said that it was OK. I forwarded a few posts from the internet to my service advisor. A few days later when I called to check on the transmission part, he stated that they checked the controller and found a fault and that they were going to replace it.

We have a 2024 2500 Sierra that we bought off of the lot. It is a basic work truck with the 6.6L gas engine. It has 8000 miles and is currently in the shop needing a valve body for the transmission. It has been in the shop 3 weeks and the part is on backorder. GM is unable to give information on when the part will be available. At first it was between 7/31 to 8/13. The dealer now says 8/14 to 8/26. The customer service people are nice but have no authority and will not let you speak to upper management. I use the vehicle to tow and the dealer does not have a 2500 loaner. GMC will not authorize the cost to rent an equivalent vehicle. They would only state that their policy would reimburse me less than 50% of the cost and I could send them the bill for further consideration. We have averaged 11.5 - 12 mpg in the city. Highway was 13.5 - 15 mpg. Towing is another story. On a recent trip to pick up a pontoon boat in Florida we averaged 5.7 mpg at 65 miles per hour. It tows reasonably well for a gas engine. The boat and trailer combined weight was around 7800 lbs. If you are considering using the truck for towing be aware that we have had problems with the trailer brake controller. Under normal driving conditions, the truck will randomly display "Trailer wiring fault". During this time that will last from 3 to 60 seconds the trailer has no brakes. Recently with an 11,000 gross weight trailer and load, we were pushed through a red light with the antilock brakes chattering so bad that I thought that the truck was going to shake apart. GM has stated that they do not have a problem with the controller but if you search the internet you will find many articles regarding this. A dealership checked the controller and said that it was OK. I forwarded a few posts from the internet to my service advisor. A few days later when I called to check on the transmission part, he stated that they checked the controller and found a fault and that they were going to replace it.

I have a 2024 GMC 2500 HD and tow 10,000 lb man lift-total load with trailer 12,500lbs. The trailer has hydraulics to tilt the trailer and a lead acid battery to power this. We do not have a solar panel attached to the system. We are having a problem with our electronic controller. It intermittantly posts a message "check trailer wiring" and during this time there are no trailer brakes. We have towed the same trailer with two other vehicles and do not have a problem. We have had the trailer checked and cannot find a wiring problem. GMC has refused to put me into contact with a regional service tech that has technological knowlege regarding this subject. Some of the online posts that we have read state that solar chargers can and input higher voltage than the tow wehicle battery voltage causing interfearance with the controller. As stated above we do not have a solar charger, but the trailer battery does have a higher voltage reading than our tow vehicle, and we are experiencing the same problems. My question is what might happen if ther battery on the tow vehicle becomes slightly run down, the truck starts but now the voltage in the tow vehicle is less than the battery in the trailer. Does this mean that there could be brake malfunction? This is a severe safety issue. We have been able to eliminate the warning message by pulling the the trailer charging fuse in the vehicle fuse block (#84). We have also been able to eliminate the message by disconnecting the emergency brake positive lead from the trailer battery which eliminates the triler emergency brakles. Both of these solutions indicate that GMC has a problem with their controller. GMC promotes their trucks as GMC grade Professionsal Grade. You would think that their Professional Grade engineers would be aware of the different trailer types and wiring configurations when they designed the electronic controller. Apparently not as they refuse to admit that they have a problem. I urge everyone to file a complaint with the NTSB before someone is killed or injured as a result of a faulty controller.