Powertrain Control Module (PCM)
P0462-FUEL LEVEL SENSOR 1 CIRCUIT LOW
For a complete wiring diagram, refer to the Wiring Information. Electrical Diagrams
Theory of Operation
Vehicles with saddle fuel tank configurations have two fuel level sending units. The primary side of the tank (left side of vehicle) 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 (right side of vehicle). 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:
With the ignition on and battery voltage greater than 10.4 volts.
- Set Condition:
The Fuel Level Sensor 1 input voltage is 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. DTC IS ACTIVE
NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.
NOTE: Diagnose and repair any communication DTCs before continuing with this test.
1. Start the engine and allow it to reach operating temperature.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hand near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.
2. With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. Checking for an Intermittent DTC.
2. (N4) FUEL LEVEL SIGNAL 1 CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Disconnect the Fuel Pump Module harness connector.
3. Disconnect the C2 Cluster (CCN) harness connector.
4. Measure the resistance between ground and the (N4) Fuel Level Signal 1 circuit in the Fuel Pump Module harness connector.
Is the resistance above 100 Ohms?
Yes
- Go To 3
No
- Repair the short to ground I the (N4) Fuel Level Signal 1 circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
3. (N4) FUEL LEVEL SIGNAL 1 CIRCUIT OPEN CIRCUIT OR HIGH RESISTANCE
1. Measure the resistance of the (N4) Fuel Level Signal 1 circuit between the Fuel Pump Module harness connector and the C2 Cluster (CCN) harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 4
No
- Repair the excessive resistance in the (N4) Fuel Level Signal 1 circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
4. FUEL TANK WIRING HARNESS INSPECTION
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.
2. Inspect the wiring and connectors between the Fuel Pump Module harness connector and the Fuel Level Sensor 1 connector.
3. Look for any chafed, pierced, pinched, shorted or broken wires.
4. Look for broken, bent, pushed out or corroded terminals.
Were any problems found?
Yes
- Repair as necessary.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Go To 5
5. FUEL LEVEL SENSOR 1
1. Turn the ignition off.
2. Connect the Fuel Pump Module harness connector.
3. Connect the C2 Cluster (CCN) harness connector.
4. Turn the ignition on.
5. With the scan tool, read the Fuel Level Sensor 1 signal voltage.
NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 of a volt) with the Fuel Level Sensor 1 harness connector disconnected.
Does the scan tool display the voltage as described above?
Yes
- Replace the Fuel Level Sensor 1.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Go To 6
6. CLUSTER (CCN)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Level Sensor 1 harness connector and the Cluster (CCN).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Replace and program the Cluster (CCN).
- Perform the BODY VERIFICATION TEST. Body Verification Test.