DTC Descriptors
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.
- DTC P0401
-
Exhaust Gas Recirculation (EGR) Flow Insufficient
- DTC P0402
-
Exhaust Gas Recirculation (EGR) Flow Excessive