Conditions for Running the DTC

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 speed is greater than 400 RPM.
The ignition voltage is between 9-18 volts.
DTC P3401, P3425, P3441, and P3449 runs continuously when the above conditions are met.