The DEF system on this vehicle has failed three times since we bought it in 2021. The weather was not pleasant and in one case it was extremely dangerous. The DEF system froze up and fortunately I was able to limp it into a dealer who managed to get it working again but not after losing half a day and spending a couple hundred dollars. The second time a sensor failed and I was able to reset the system myself via removing all the electricity from the vehicle and doing what they call a shady tree reset. The third time the vehicle went into limp mode on us was when a sensor failed and the DEF pump failed at the same time. Chevy refused to help us cover the cost of repairs and refuses to replace the defective system. The vehicle might be over ten years old but it is like showroom new, it only had 20,000 miles on it in 2021 when we bought it and the previous owner took very good care of the truck. The vehicle now only has 32,000 miles on it. Our main argument is that Chevy aka GM knows about the defective systems and refuses to replace them. I have been in the transportation industry for a good part of my life and I know vehicles, especially diesel operated vehicles. The DEF systems are a complete joke and need to be removed especially for people who live in very cold climates.
NHTSA ODI 11479129