Conditions for Running the DTC: P040C

WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The engine is running for 30 seconds or longer.
The engine coolant temperature is 60°C (140°F) or warmer.
The engine is not in diesel particulate filter (DPF) regeneration.
This DTC runs continuously when the above conditions are met.
The EGR valve is open more than 4 percent.