DTC P0461-Fuel Level Sensor 1 Performance: Notes

Fig 1: Fuel Level Sensor Circuit - Circuit Diagram

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article.

Theory of Operation 

The fuel level rationality will set a fault for a fuel level reading that does not change over an accumulated mileage threshold to keep stuck high or stuck low fuel levels from disabling OBD monitors. If the vehicle is fitted with a saddle tank fuel system this feature includes diagnostics for both of the sending units and diagnostics for a siphon tube that has become disconnected or plugged. The power up test looks to see a large enough fuel level voltage change from the last key-off to the following engine run. The engine run test looks to see a fuel level voltage change over an accumulated mileage. 

• When Monitored: 

  TEST No. 1: With the ignition on, the fuel level is compared to the previous key down after a 20 second delay. TEST No. 2: The PCM monitors the fuel level at ignition on. 

• Set Condition: 

  TEST No. 1: If the PCM does not see a difference in fuel level of greater than 0.1 volt the test will fail. TEST No. 2: If the PCM does not see a change in the fuel level of.1765 over a set amount of miles the test will fail. Three good trips to turn off the MIL. 

Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding.