Conditions For Setting DTC

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The fuel temperature and the ECT are more than 18°F (9.8°C) of each other at start-up.
The IAT has dropped less than 10°F (5.3°C) after running more than 400 seconds above 15 MPH.