'09 Chevy HD

rnemerson · January 14, 2015

Towing my stock trailer the transmission will lock me out of 5th & 6th gear. This doesn't happen immediately but it does happen every time I pull a big trailer. When I stop and turn the truck off, start it again and go, it's like it resets and all is good for a short time and boom, there it goes again. Any ideas?

gmtech4 · January 15, 2015

Scan it to start !!

Big Whiskey · January 16, 2015

Are you using tow/haul mode? How heavy is the trailer? What speeds are you traveling? Gas or diesel? Are there any warnings lights on the dash?

rnemerson · January 16, 2015

Are you using tow/haul mode? How heavy is the trailer? What speeds are you traveling? Gas or diesel? Are there any warnings lights on the dash?

Tow/Haul yes, always when I tow. Trailer weighs 6,000lbs. I notice the lock out almost always at 60-65 mph. 6.0 liter gas. Check engine light comes on and gives a code P0741 & one other that I don't recall now but both are from the trans. The dealer replaced the TCM and I think it was a solenoid in the tranny. Now the 5-6 lockout happens more often and it seems to happen much quicker. That truck shouldn't have any problem pulling that trailer. My '02 light duty 3/4 ton never did any of this even with 260k miles. The biggest problem is all of this started while under GM 100k warranty and they aren't wanting to do anything but give me the run around.

gmtech4 · January 16, 2015

Tow/Haul yes, always when I tow. Trailer weighs 6,000lbs. I notice the lock out almost always at 60-65 mph. 6.0 liter gas. Check engine light comes on and gives a code P0741 & one other that I don't recall now but both are from the trans. The dealer replaced the TCM and I think it was a solenoid in the tranny. Now the 5-6 lockout happens more often and it seems to happen much quicker. That truck shouldn't have any problem pulling that trailer. My '02 light duty 3/4 ton never did any of this even with 260k miles. The biggest problem is all of this started while under GM 100k warranty and they aren't wanting to do anything but give me the run around.

Go to a different dealer

02suburbanZ71 · January 17, 2015

I think the 02's are a little more reliable lol

Big Whiskey · January 18, 2015

Tow/Haul yes, always when I tow. Trailer weighs 6,000lbs. I notice the lock out almost always at 60-65 mph. 6.0 liter gas. Check engine light comes on and gives a code P0741 & one other that I don't recall now but both are from the trans. The dealer replaced the TCM and I think it was a solenoid in the tranny. Now the 5-6 lockout happens more often and it seems to happen much quicker. That truck shouldn't have any problem pulling that trailer. My '02 light duty 3/4 ton never did any of this even with 260k miles. The biggest problem is all of this started while under GM 100k warranty and they aren't wanting to do anything but give me the run around.

Yeah that sounds like something the dealer needs to fix. And, if you're not getting the help you need, take it to a different dealer.

rnemerson · January 19, 2015

I'm going to stay on it that's for sure. Other than being frustrated with how my truck is performing, I guess I'm really disappointed with the dealer's crap and with GM. I was informed, by the dealer, that there was a bulletin on this transmission concerning the problem I'm having. The bulletin offers no fix. It sounds like a way out for GM. I wonder how many trucks GM would sell if they told perspective buyers the transmissions in the HD trucks, when towing a load, do not shift properly. This is to protect the engine and transmission from damage caused by overworking the powertrain due to towing loads less than GM says the trucks are rated for. I've been a CHEVY man all my life and will continue to be one but for now I'm just disappointed. Thanks for listening guys. If something happens, I'll post about it.

newdude · February 2, 2015

Those codes have full diagnostic procedures that should be followed by the dealer. P0741 is Torque Converter Clutch (TCC) – Stuck Off – Transmission Hydraulic/Mechanical Performance.

rnemerson · February 4, 2015

Those codes have full diagnostic procedures that should be followed by the dealer. P0741 is Torque Converter Clutch (TCC) – Stuck Off – Transmission Hydraulic/Mechanical Performance.

Yeah, I know the code definition well! The problem is they cant get it to throw any codes when they have it. Time after time I've told them to let me hook up the trailer and come get the trans tech, hook his equipment up and go for a little ride but they aren't willing. It seems like the service manager is just leaning on that bulletin he found and that's his way out of spending any more time on it. For now I'm relaxing and getting all of the paperwork together to present to my attorney if taking it to another dealer fails. I paid too much money for that truck to let GM just brush me off. In the meantime, I'm going to use it for what I bought it for...Towin' that load!