The fuel level sensor change resistance based on fuel level. The engine control module (ECM) monitors the signal circuits of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the resistances of the fuel level sensor is low and the ECM senses a low signal voltage on the signal circuits of the fuel level sensor. When the fuel tank is empty, the resistances of the fuel level sensor is high and the ECM senses a high signal voltage. The ECM uses the signal circuits of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via High Speed CAN-Bus to the body control module (BCM). The BCM then sends the fuel level percentage via Low Speed CAN-Bus to the instrument cluster in order to control the fuel gage.

P0462

P0463

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Instrument Cluster Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool ECM - Fuel Level Sensor parameter. The reading should be 1-4 V.

1. Ignition OFF, disconnect the harness connector at the G12 Fuel Pump.
2. Ignition OFF, test for less than 5 Ω between the low reference circuit terminal 2 and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

3. Ignition ON, verify the scan tool ECM - Fuel Level Sensor parameter is greater than 4 V.

⇒	If less than the specified range, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

4. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool ECM - Fuel Level Sensor is less than 1 V.

⇒	If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

5. If all circuits test normal, test or replace the appropriate sensor.

Static Test

1. Ignition OFF, disconnect the harness connector at the G12 Fuel Pump.
2. Test for 20-300 Ω between the signal terminal 1 and the low reference circuit terminal 2.

⇒	If not within the specified range, replace the G12 Fuel Pump.

3. Test for infinite resistance between each terminal and the sensor housing/case.

⇒	If less than the specified value, replace the G12 Fuel Pump.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.