P0462-FUEL LEVEL SENSOR 1 CIRCUIT LOW

For a complete wiring diagram Refer to Section 8W.

When Monitored:
Ignition on and battery voltage above 10.4 volts.
Set Condition:
The fuel level sensor signal voltage goes below 0.4 of a volt for more than 90 seconds. One Trip Fault. Three good trips to turn off the MIL.

(N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO GROUND

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - SCHEMATICS AND DIAGRAMS).

Diagnostic Test

1. FUEL LEVEL SENSOR VOLTAGE BELOW 0.4 OF A VOLT

NOTE: Diagnose any CAN - B or CAN -C Communication DTCs before continuing.

Ignition on, engine not running.
With the scan tool, read the Fuel Level Sensor voltage.

Is the Fuel Level Sensor voltage below 0.4 of a volt?

Yes

Go To 2

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2. FUEL LEVEL SENSOR

Turn the ignition off.
Disconnect the Fuel Pump Module harness connector.
Ignition on, engine not running.
Using a fused jumper wire, jump the (A109) Fused B+ circuit to the (N4) Fuel Level Sensor No.1 Signal circuit in the Fuel Pump Motor harness connector.

Did the Fuel gauge level change from empty to full?

Yes

Replace the Fuel Level Sensor.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 3

3. (A109) FUSED B+ CIRCUIT

Using a 12-volt test light connected to ground, probe the (A109) Fused B+ circuit.

Does the test light illuminate brightly?

Yes

Go To 4

Repair the open or short to ground in the (A109) Fused B+ circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

4. (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO GROUND

Turn the ignition off.
Disconnect the C1 Cluster harness connector.
Measure the resistance between ground and the (N4) Fuel Level Signal circuit in the Fuel Pump Module harness connector.

Is the resistance below 100 ohms?

Yes

Repair the short to ground in the (N4) Fuel Level Signal circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 5

5. (N4) FUEL LEVEL SIGNAL CIRCUIT OPEN

Measure the resistance of the (N4) Fuel Level Signal circuit from the Fuel Pump Module harness connector to the C1 Cluster harness connector.

Is the resistance below 5.0 ohms?

Yes

Go To 6

Repair the open in the (N4) Fuel Level Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

6. INSTRUMENT CLUSTER

NOTE: Before continuing, check the Instrument Cluster harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes

Repair as necessary.

Perform BODY VERIFICATION TEST. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)

Replace and program the Instrument Cluster per Service Information.
Perform BODY VERIFICATION TEST. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)