Circuit Description

PCM monitors fuel level sensor. This is an important input to the PCM for enhanced evaporative system diagnostic. PCM needs fuel level information for determining volume of fuel in the tank. Enhanced evaporative system diagnostic test needs fuel level input to gauge the rate of change in air pressure in the EVAP system. Enhanced evaporative system diagnostic test will not be performed when fuel level is greater than 85 percent or less than 15 percent.

Conditions required for setting DTC are:

• Fuel tank level slosh test is completed.
• Tank level main test is completed.
• Fuel tank level data is valid.
• Fuel level signal changes by less than .06 volts for a period greater than 20 seconds.