Circuit Description

The fuel level sensor is mounted in the fuel level sensor unit. The sensor detects fuel level in the fuel tank and transmits a signal to the ECM. It consists of 2 parts. One is the mechanical float and the other is a variable resistor. Fuel level sensor output voltage changes depending on movement of the fuel mechanical float.

Driving long distances naturally affects fuel gauge level. This diagnosis detects fuel gauge malfunction. Gauge does not move even after a long distance has been driven.