Circuit Description

Fuel level is an important input to PCM for Enhanced Evaporative System Diagnosis (EESD). Fuel level information is needed by PCM to determine volume of fuel in fuel tank. Fuel level affects rate of change in air pressure in EVAP system. Fuel sending unit is a float in fuel tank which moves a wiper across a variable resistor. Low fuel level causes high resistance in fuel sending unit, and is recognized by PCM as corresponding low voltage. If PCM detects a continuous open or high resistance in fuel level sensor or circuit, DTC P0464 will set.