Circuit/System Description

Single Sensor System 

The fuel level sensor changes resistance based on fuel level. The Fuel Pump Driver Control Module monitors the signal circuit of the fuel level sensor and sends the signal information to the Engine Control Module (ECM) for further handling. The ECM uses this value to determine the fuel level. When the fuel tank is full, the resistance of the fuel level sensor is low and the ECM senses a low signal voltage on the signal circuit of the fuel level sensor. When the fuel tank is empty, the resistance of the fuel level sensor is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via the serial data circuit to the Instrument Cluster in order to control the fuel gauge.

Dual Sensor System 

The primary fuel level sensor and the secondary fuel level sensor change resistance based on fuel level. The Fuel Pump Driver Control Module monitors the signal circuits of the primary fuel level sensor and the secondary fuel level sensor and sends the signal information to the Engine Control Module (ECM) for all further handling. The ECM uses this value to determine the fuel level. When the fuel tank is full, the resistances of both fuel level sensors are low and the ECM senses a low signal voltage on both the signal circuits of the primary fuel level sensor and the secondary fuel level sensor. When the fuel tank is empty, the resistances of the fuel level sensors are high and the ECM senses a high signal voltage. The ECM uses the signal circuits of the primary fuel level sensor and the secondary fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via the serial data circuit to the Instrument Cluster in order to control the fuel gauge.