GM Duramax diesel DEF tank failures are increasingly popping up in social media and owners are furious about the problems around the issues with the trucks. These complaints keep popping up on various Facebook groups, forums and NHTSA.gov complaints I’ve been reading. These reports describe warning messages, speed-limiting “derate” modes and lengthy (think months) waits for replacement parts. While the issue is often described as a “DEF tank failure,” most reports point to problems with components integrated into the tank module rather than the plastic tank itself. Warning Messages and Speed-Limited Driving One of the most common issues described in […] (read full article...)