DTC P0168: Fuel Temperature Sensor High: Description
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The fuel temperature sensor is a thermistor type sensor. The Engine Control Module (ECM) supplies 5 volts and a ground circuit to the sensor. When the ECM detects a fuel temperature sensor above a pre-determined value, a type C code, no Malfunction Indicator Lamp (MIL) sets. A fuel cooler located in front of the fuel tank is used to help keep the fuel temperature at an acceptable limit.