Conditions For Setting DTC

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Sonoma, 2002 GMC Safari, 2002 GMC Jimmy, 2002 Chevrolet S10 Pickup, and 2002 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.

If the PCM detects a temperature difference of more than 27°F (15°C) between the ECT and the IAT, the vehicle must be driven for 7 minutes over 15 MPH. If the IAT decreases more than 5.4°F (3°C) then a block heater is indicated and the test is aborted. If the IAT temperature does not decrease, a block heater was not detected and this DTC will set; or, the temperature difference between the ECT and the IAT at start up is more than 252°F (140°C).
The time spent cranking the engine, without starting is more than 10 seconds.