Conditions for Running the DTC

WARNING: This page is about a different car, the 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 Chevrolet TrailBlazer, and 2004 Buick Rainier. However, it is still accessible from the selected car via links, so may be relevant.

DTCs P0601, P0602, P0604, P0606, P1516, P2108, U0107 are not set.
DTCs P0120, P0220, P2135 are not active at the same time.
DTCs P0120 and P0220 are not active at the same time.
The ignition switch is in the crank or run position.
The ignition voltage is more than 8.5 volts.
The TAC system is not in the battery saver mode.