Powertrain Control Module (PCM)

P0462-FUEL LEVEL SENSOR 1 CIRCUIT LOW





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Fuel Level Sensor information is a bussed message to the Powertrain Control Module (PCM) from the Body Control Module (BCM). Vehicles fitted with saddle fuel tank configurations have two Fuel Level Sensors. The primary side of the tank has the filler tube inlet near the bottom and contains the fuel pump module. During fuel tank fills, fuel must overflow the primary side to reach the secondary side of the tank. As fuel is consumed, a siphon tube is used to draw fuel from the secondary side to the primary side. Because the siphon tube flow rate exceeds the fuel consumption rate, the secondary side of the tank will be empty before fuel is depleted from the primary side. Fuel Level Sensor 1 is located on the primary side of the tank. Fuel Level Sensor 2 is located on the secondary side of the tank.

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

- Set Condition:
The Fuel Level Sensor signal voltage goes below the minimum acceptable value. One Trip Fault. Three good trips to turn off the MIL.





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

1. ACTIVE DTC

NOTE: Diagnose any Communication DTCs before continuing.

1. Turn the ignition on.
2. With the scan tool, clear all DTCs.
3. Cycle the ignition off for 30 seconds, and then back on.
4. With the scan tool, select View DTCs.

Is the DTC Active or Pending at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. FUEL LEVEL SENSOR CIRCUIT DTCs SET IN THE CCN

Are any Fuel Level Sensor Circuit DTCs set in the CCN?

Yes

- Diagnose the appropriate Fuel Level Sensor Circuit DTC in the CCN. Testing and Inspection.

No

- Go To 3

3. VISUALLY INSPECT FUEL TANK
1. Visually inspect the Fuel Tank for damage that may restrict the Fuel Sending Unit float from moving.

Is the Fuel Tank OK?

Yes

- Go To 4

No

- Replace the Fuel Tank as necessary. Fuel Tank - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. INTERNAL INSPECTION OF THE FUEL TANK

WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.

1. Remove the Fuel Tank. Fuel Tank - Removal.
2. Remove the Fuel Pump Module. Fuel Pump Module - Removal.
3. Visually inspect the inside of the Fuel Tank for any obstructions or deformities.
4. Inspect the Fuel Pump Module Float arm for damage.

Were any problems found?

Yes

- Repair or replace as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 5

5. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Body Control Module (BCM) and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Sensor and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module. Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.