Conditions For Setting DTC
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Sierra, 2002 GMC Savana Special, 2002 GMC Savana Camper Special, and 2002 GMC Savana. However, it is still accessible from the selected car via links, so may be relevant.
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 7 minutes over 15 MPH. If the IAT sensor temperature decreases more than 5.4°F (3°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; or the temperature difference between the ECT and the IAT at start-up is more than 252°F (140°C) and the time spent cranking the engine, without starting is more than 10 seconds.