NHTSA Complaint #11672213 — 2020 CHEVROLET SILVERADO 1500

My 2020 Chevrolet Silverado 1500 LT with the 3.0L Duramax diesel engine has experienced three separate failures of the coolant control valve over a span of less than two years. Each failure resulted in the vehicle entering reduced engine power mode, which drastically limits acceleration and the ability to maintain safe driving speeds — particularly dangerous on highways or in heavy traffic. Chronology of Failures: October 2023: First coolant control valve failure. Part was backordered. Repair took ~6 weeks. June 2024: Second failure of the same part. Another 6-week delay in repair due to part availability. June 2025: Third failure of the same part. Vehicle is currently inoperable and unsafe to drive. Each time, the failure triggered a check engine light and immediately placed the truck into reduced power mode. This issue significantly compromises driver safety, especially in high-speed or congested environments, where limited acceleration can increase the risk of collisions. Safety Concerns: Loss of acceleration power at critical times (merging, overtaking, etc.) Unpredictable vehicle behavior Extended unavailability of parts leads to prolonged periods without a functional vehicle Possible underlying design flaw or recurring part defect Given the recurrence, safety risks, and the number of similar complaints I have seen from other owners, I believe this is a widespread and systemic defect that deserves NHTSA investigation. Requested Action: I urge the NHTSA to investigate the frequency and root cause of coolant control valve failures on the 3.0L Duramax engine in the 2020–2022 Silverado models. This is not an isolated incident, and repeated failures of a critical engine cooling component warrant a safety recall or technical service bulletin (TSB) requiring redesign or replacement with a permanent fix.