Conditions For Setting DTC
If the PCM detects a temperature difference between the ECT sensor and the IAT sensor of more than 27°F (15°C), the vehicle must be driven for 5 minutes over 15 MPH. If the IAT sensor temperature decreases more than 12.6°F (7°C), a block heater is detected and the test is aborted. If the IAT sensor temperature does not decrease, a block heater was not detected and DTC P0116 sets.