DTC P0169: Fuel Composition Sensor - High Alcohol Content Detected (5.3L Flex-Fuel): Description

The Powertrain Control Module (PCM) uses information from the IAT and the ECT sensors to determine ambient temperature at cold start-up. Alcohol content (percentage) information is supplied to the PCM fro the fuel composition sensor. This information is used by the technician in diagnosing symptom related complaints such as hard starting in cold ambient temperatures. The PCM monitors the fuel frequency during the first 30 seconds of run time. When the PCM detects alcohol content that is too high for a given ambient temperature, this DTC sets.