Conditions For Setting The DTC

WARNING: This page is about a different car, the 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, 2003 Chevrolet Monte Carlo, and 2003 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

The PCM detects a temperature difference between the ECT sensor and the IAT sensor of more than 180°F (100°C) at start up.
The time spent cranking the engine, without starting is more than 5 seconds with a temperature difference between the ECT sensor and the IAT sensor more than 27°F (15°C).
The PCM detects a temperature difference between the ECT sensor and the IAT sensor of more than 27°F (15°C), then the vehicle must be driven for 5 minutes over 15 MPH. If the IAT sensor temperature decreases more than 12.6°F (7°C) then a block heater is detected and the test is aborted. If the IAT sensor temperature does not decrease, than a block heater was not detected and DTC P0116 sets.