Fuel Gauge Does Not Read Full When Fuel Tank is Full, Service Engine Soon (SES) Light On, Diagnostic Trouble Code (DTC) P0455 (Inspect Fuel Level Sensor Operation)

The most likely cause is a deformed fuel tank. During production of the fuel tank, the tank may have become deformed not allowing the sending unit arm to travel to the full/up position. It is possible that a faulty fuel level sensor could be the cause also.

Follow the diagnostic and repair procedure below to correct this condition.

1. Test the fuel gauge operation. Refer to Fuel Gage Inaccurate or Inoperative, SI Document ID #1461571.

•	If the diagnosis leads to something other than the fuel level sending unit, continue with the appropriate diagnosis in SI.

•	If the diagnosis leads to the fuel level sending unit, continue with the next step.

2. Remove the fuel sender assembly from the vehicle. Refer to Fuel Sender Assembly Replacement, Malibu MAXX SI Document ID #1479778.
3. Test the fuel level sensor with a DMM. While moving the sensor from full to empty, the resistance should change between 40ohms and 250ohms. Refer to Fuel Level Specifications Extended Sedan SI Document ID #1435113.

•	If the fuel level sensor is not within specification, replace the fuel level sending unit, P/N 22677575. Refer to Fuel Level Sensor Replacement Malibu MAXX SI Document ID #1479765.

•	If the fuel level sensor is within specification, continue with the next step.

4. Replace the fuel tank, P/N 22677577. Fuel Tank Replacement Malibu MAXX SI Document ID # 1479761.

Parts are expected to be available from GMSPO on October 29, 2004.

For vehicles repaired under warranty, use: