Diagnostic Aids

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Ensure that an engine block heater or front grill blanket is not being used at temperatures above -17C ( 0°F ).
A engine block heater is used at temperatures above -17C ( 0°F ) this DTC may set.
A front grill blanket is used at temperatures above -17C ( 0°F ) this DTC may set.
If this DTC cannot be duplicated, the conditions may be intermittent. Refer to Intermittent Conditions .