P0462

P0462-FUEL LEVEL SENSOR 1 CIRCUIT LOW




For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
Theory of Operation

The fuel level sending unit is attached to the side of the fuel pump module. The sending unit consists of a float, an arm and a variable resistor track (card). The fuel transfer pump is also attached to the fuel pump module. A 5-volt reference signal is supplied to the resistor track of the fuel gauge sending unit. The resistor track is a variable resistor used to vary the voltage signal depending on fuel tank float position. As fuel level increases, the float and arm move up, which decreases voltage. As fuel level decreases, the float and arm move down which increases voltage. When the fuel tank level is measured below 15%, the following fuel system monitors are shut off: P0191 (Fuel Pressure Idle Diagnostic portion of it), and DTCs P0300, P0301, P0302, P0303, P0304, P0305, P0306. The Cluster/CCN will illuminate the MIL lamp immediately after this diagnostic runs and fails. The CCN will turn off the MIL lamp after the diagnostic runs and passes in 4 consecutive drive cycles.

- When Monitored:
Ignition on and battery voltage above 10.4 volts.

- Set Condition:
The signal voltage from the sensor falls below a calibrated value for a calibrated amount of time.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool check for active DTCs.

Is the DTC active?

Yes

- Go To 2

No

- Perform the INTERMITTENT DTC diagnostic procedure. Intermittent Condition Test.

2. FUEL LEVEL SENSOR
1. Ignition on, engine not running.
2. Disconnect the Fuel Pump Module harness connector.
3. With the scan tool check for DTC P0463.

Did DTC P0463 set after unplugging sensor?

Yes

- Replace the Fuel Level Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. FUEL LEVEL SENSOR SIGNAL CIRCUIT SHORTED TO GROUND




1. Turn ignition off.
2. Disconnect the Cluster C4 harness connector.
3. Measure the resistance between ground and the (N4) Fuel Level Sensor Signal circuit at the CCN C4 harness connector.

Is the resistance less than 10k Ohms?

Yes

- Repair the short to ground in the (N4) Fuel Level Sensor Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 4

4. FUEL LEVEL SENSOR SIGNAL CIRCUIT SHORTED TO THE (Z210) FUEL LEVEL SENSOR RETURN CIRCUIT




1. Measure the resistance between the (N4) Fuel Level Sensor Signal circuit and the (Z210) Fuel Level Sensor Return circuit at the Cluster harness connectors.

Is the resistance less than 10k Ohms?

Yes

- Repair the short between the (N4) Fuel Level Sensor Signal circuit and the (Z210) Fuel Level Sensor Return circuit.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace the Cluster.
- Perform the BODY VERIFICATION TEST. Body Verification Test.