NHTSA Complaint #11710279 — 2020 CHEVROLET SILVERADO 1500

The contact owns a 2020 Chevrolet Silverado 1500. While operating in negative (-41°F) degree winter conditions, the "Service Emission System" entered an EPA-mandated speed limitation in LIMP Mode messages were displayed. Dealer diagnostics confirmed DTC: P20B9 (Heater Control Circuit Open) and P20C1. The failure was identified as the melting of the Diesel Exhaust Fluid (DEF) tank electrical connector due to undersized terminal pins overheating (Joule heating). The contact stated that it was a latent design defect that posed a fire risk and a safety hazard due to sudden loss of motive power in arctic climates (-45°F). General Motors acknowledged the defect in 2500HD models, Special Coverage: N212342980; but excluded the 1500 models. The failure mileage was 29,354.