Circuit Description

WARNING: This page is about a different car, the 2002 GMC Sonoma and 2002 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.

The Powertrain Control Module (PCM) uses information from the Intake Air Temperature (IAT) and the Engine Coolant Temperature (ECT) sensors to determine ambient temperature at cold start-up. Alcohol content, alcohol percentage, information is supplied to the PCM from the Fuel Composition Sensor (FCS). When the alcohol content is too high for a given ambient temperature an internal DTC will set in the PCM. This code is for information only, in order to aid the technician for symptom related complaints such as hard starting in cold ambient temperatures due to fuel blends which are not recommended for the ambient temperature. In some cases the DTC may set if there is contamination present in the fuel causing the calculated alcohol content to be higher than expected.