GM has released new service information addressing a 3.0 Duramax condition where the engine idles normally but hesitates, loses power, or stalls during acceleration. The cause points to an internal restriction in the charge air cooler hose — a component critical to proper boost and airflow on both LM2 and LZ0 engines.

GM bulletin PIT5689M addresses no-restart after Auto Stop, intermittent no-crank, dead battery, glow plug faults, transfer case errors, and multiple warning lights on Silverado and Sierra trucks. The root cause is often a loose or damaged engine-to-body ground at the passenger-side firewall (G132/G134). Inspecting and securing this ground can prevent widespread electrical faults and unnecessary parts replacement.

P2C7A on the 3.0 Duramax means the SCR/NOx catalyst isn’t meeting efficiency. Learn the real causes, exact diagnostics, and fixes for LM2/LZ0.

If you’re a 3.0 Duramax Diesel owner, you’ve likely heard of the P04FB code—it’s one of the most common diagnostic trouble codes (DTCs)...