Conditions for Running the DTC

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

P2600, P2602, or P2603

The engine speed is greater than 80 RPM.
The ignition voltage is between 10-18 volts.
The ECM has commanded the pump ON and OFF at least once during the ignition cycle.
The DTCs run continuously once the above conditions are met.

P2601

DTCs P0111, P0112, P0113, P0116, P0117, P0118, P0119, P02600, P02602, and P02603 are not set.
The engine coolant temperature at shut down is greater than 110 °C (230 °F) for longer than 70 seconds.
The DTC run continuously once the above conditions are met.