Conditions For Running DTC

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

DTCs P0601, P0602, P0604, P0606, P1515, P1516, P1517, or P1518 are not set.
DTCs P1120, P1220 and P1221 are not set at the same time or DTCs P1120 and P1220 are not set at the same time.
The engine operates longer than 1 second.
The engine speed is greater than 500 RPM.