GMC Sierra 1500

"The DEF system has either defective software or defective sensors. When towing the DEF system uses excessive DEF fluid. Also the system that estimates the distance you can go before you run out of DEF and going into limp mode (speed limited to 55 mph) is 100% wrong all the time. The gage that shows how much DEF you have is wrong pretty much all the time. It will sometimes go from showing 3/4 full to empty in 10 miles. Then it starts counting down the miles you can go until the vehicle goes into limp mode (speed limited) The estimated miles to go is always wrong by a big margin. I took it into the dealer and they replaced the DEF tank and sensor. It made no difference. It makes me think the software that tracks and calculates the DEF level and miles to empty is flawed. I have talked to the service manager and the GM Certified mechanic who worked on the truck and apparently GM has no answer for this issue. I have several friends who own 3.0 liter diesel half tons and they are all having the same problem. The dealer gave me a copy of the technical service bulletin telling me how and when to refill the DEF tank and that was completely useless. GM needs to get their arms around this issue. I have friends who have traded their otherwise great GM trucks in for another vehicle over this DEF issue. It is absurd that GM cannot fix this problem. The DEF system on GM HD's seems to work fine. I can't understand why they can't fix this"

"Fuel gauge is inaccurate. The estimated mileage remains is inaccurate."

"Fuel pump module quit working & left me stranded."

""Telematics module failed resulting in loss of compass, Google, amongst other things. Nothing that was very serious though.""

"Dashboard LEDs for heated/cooled seats were not working and needed to be replaced."

""cuts in and out on sound, been at shop 5 times for it.Still does it after numerous software updates by GMC""

"They will just stop or hesitate when using them. No pattern as to why or when it will occur. Doesn't code the engine so impossible to recreate at dealer foe diagnosis"

"Power windows- make weird noises like it isnt positionwd on the roller correctly. Again can't be diagnosed by dealer"