Enabling/Set Conditions And Possible Causes - Fuel Level Sensor Faults

When Monitored - Circuit Faults (P0462, P0463, P2067, P2068, P2065-11, P2065-15):

These diagnostics run when the following conditions are met:

When Monitored - Rationality Faults (P0461, P2066):

These diagnostics run when the following conditions are met:

Single Tank System:

With the engine running for more than two minutes.
After the PCM decides that a calibrated amount of fuel should have been consumed (between approximately one and five gallons depending on initial fuel level).
- This is determined by the accumulated amount of fuel injected into the engine through the Fuel Injectors.

Saddle Tank System:

The primary level rationality diagnostic runs when the Fuel Level Sensor 2 (Secondary) is reading empty.
The secondary level rationality diagnostic runs when the Fuel Level Sensor 1 (Primary) is reading full.

Dual Tank System:

The primary level rationality diagnostic functions the same as the Single Tank System.
The secondary level rationality diagnostic runs when a fuel transfer event is occurring.

FAULT SETTING CRITERIA
Circuit Low/High Faults - (P0462, P0463, P2067, P2068, P2065-11, P2065-15)	Circuit Low - The Fuel Level Sensor signal voltage is below approximately 0.2 volts for more than 3.2 seconds. Circuit High - The Fuel Level Sensor signal voltage is above approximately 4.9 volts for more than 3.2 seconds.
Rationality Faults - Single Tank Systems	When the PCM does not perceive a change in fuel level of greater than 0.06 volts after the calibrated amount of fuel should have been consumed the diagnostic will fail.
Rationality Faults - Saddle Tank Systems	Primary Fault (P0461) - If the PCM does not perceive a change in Fuel Level Sensor 1 of greater than 0.06 volts after the calibrated amount of fuel should have been consumed the diagnostic will fail. Secondary Fault (P2066) - If the PCM does not perceive a change in Fuel Level Sensor 2 of greater than 0.06 volts after the calibrated amount of fuel should have been consumed the diagnostic will fail.
Rationality Faults - Dual Tank Systems	Primary Fault (P0461) - If the PCM does not perceive a change in fuel level of greater than 0.06 volts after the calibrated amount of fuel should have been consumed the diagnostic will fail. Secondary Fault (P2066) - No change in Fuel Level Sensor 2 circuit voltage after a significant amount of fuel should have been transferred from the Auxiliary Fuel Tank to the Primary Fuel Tank.

Default Actions:

Possible Causes - Circuit Faults
FUEL LEVEL SENSOR HARNESS CONNECTOR DAMAGED OR NOT CONNECTED COMPLETELY
FUEL LEVEL SENSOR SIGNAL CIRCUIT SHORTED TO GROUND (CIRCUIT LOW FAULT)
FUEL LEVEL SENSOR SIGNAL CIRCUIT SHORTED TO THE SENSOR RETURN CIRCUIT (CIRCUIT LOW FAULT)
FUEL LEVEL SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE (CIRCUIT HIGH FAULT)
FUEL LEVEL SENSOR SIGNAL CIRCUIT OPEN/HIGH RESISTANCE (CIRCUIT HIGH FAULT)
FUEL LEVEL SENSOR RETURN CIRCUIT OPEN/HIGH RESISTANCE (CIRCUIT HIGH FAULT)
FAULTY FUEL LEVEL SENSOR
FAULTY BODY CONTROL MODULE (BCM)

Possible Causes - Rationality Faults
FUEL LEVEL SENSOR HARNESS CONNECTOR DAMAGED OR NOT CONNECTED COMPLETELY
FUEL TANK DAMAGED
OBSTRUCTION TO THE PRIMARY OR SECONDARY FUEL LEVEL SENSOR
PRIMARY OR SECONDARY FUEL LEVEL SENSOR FAULTY OR BROKEN
SECONDARY PUMP OR SIPHON TUBE LEAKING OR DISCONNECTED (SADDLE TANK SYSTEM)
POWERTRAIN CONTROL MODULE (PCM)

Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding. Refer to: PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .