Diagnostic Aids

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: When inspecting for a deformed or a warped fuel tank, measure the resistance of the suspect fuel level sensor at empty, with the sensor in the fuel tank, and again with the sensor removed from the fuel tank. The measured resistance values should be the same at empty. If the measured resistance values are not the same, refer to FUEL TANKS (WITH FEEDBACK FUEL SYSTEM) or or FUEL TANKS (WITHOUT FEEDBACK FUEL SYSTEM) in Engine Performance.

Depending on the current fuel level, it may be difficult to locate a malfunctioning sending unit. The malfunction may only occur when the fuel level is full or near empty. The fuel sending unit may need to be removed for further diagnosis. A fuel level sensor that has an intermittent condition causes this DTC to set. Remove the fuel level sensor in order to test the resistance of the sensor. Refer to FUEL SENDER (WITHOUT FEEDBACK FUEL SYSTEM) or FUEL SENDER ASSEMBLY (WITH FEEDBACK FUEL SYSTEM in Engine Controls. The resistance of the sensor should change from 40 to 250 ohms as the float arm is moved from the empty to full positions. Replace the sensor if the resistance did not change or is out of range.

The following occurs with this DTC set:

The vehicle fuel gage displays empty.
The check gages indicator illuminates.
The driver information center displays a message.
If the fuel level sensor is operating OK, test the operation of the Jet Pump and the transfer function.

If DTC P0461 is also set refer to DTC P0461 (WITHOUT FFS) or DTC P0461 (W/FFS) .

For an intermittent condition, refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems.

Fig 1: DTC P1431 (W/FFS)

Courtesy of GENERAL MOTORS CORP.