Conditions for Running the DTC
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- The ECM must be commanding an active regeneration.
- DTC P0420 runs once during an active regeneration event.