Diagnostic Instructions

DTC Descriptor

DTC P0464: Fuel Level Sensor 1 Circuit Intermittent

Diagnostic Fault Information

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
Fuel Level Sensor 1 Signal Circuit	P0462	1	P0463 P0464	P0463	P0461
Fuel Level Sensor 2 Signal Circuit	P2067	1	P2068	P2068	P2066
Fuel Level Sensor Low Reference Circuit	--	1	P0463 P2068 P0464	P0463 P2068	P0461 P2066
1. Fuel Gage Inaccurate or Inoperative

Circuit/System Description

The primary fuel level sender and the secondary fuel level sender changes resistance based on fuel level. The engine control module (ECM) monitors the signal circuits of the primary fuel level sender and the secondary fuel level sender in order to determine the fuel level. When the fuel tank is full, the resistances of both fuel level senders are low and the ECM senses a low signal voltage on both the signal circuits of the primary fuel level sender and the secondary fuel level sender. When the fuel tanks are empty, the resistances of the fuel level senders are high and the ECM senses a high signal voltage. The ECM uses the signal circuits of the primary fuel level sender and the secondary fuel level sender in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via serial data circuit to the instrument cluster in order to control the fuel gage.

This diagnostic tests for an intermittent fuel level sender signal. If a change in fuel level is detected DTC P0442 is aborted due to a possible refueling event. A refueling event test is executed to confirm that a refueling event has occurred. If refueling is confirmed, the test for DTC P0464 is considered passing. The refueling event test must pass 2 out of 3 times, otherwise, the DTC will set indicating an intermittent signal problem.

Conditions for Running the DTC

Conditions for Setting the DTC

Action Taken When the DTC Sets

Conditions for Clearing the DTC

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Instrument Cluster Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 33431-C Instrument Panel Tester

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the primary fuel level sensor.
2. Ignition OFF, test for less than 1 ohm between the primary fuel level sensor low reference circuit terminal 3 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 ECM.

3. Ignition OFF, install a signal generator and instrument panel tester between the primary fuel level sensor signal circuit terminal 4 and the low reference circuit terminal 3.
4. Ignition ON, vary the signal generator resistance between 40 and 250 ohms. Verify that the scan tool Fuel Tank Level Remaining parameter displays a range that varies between 5 and 95 percent as the signal generator resistance changes.

⇒	If not displaying the specified range, test the signal circuit terminal 1 for an open/high resistance. If the circuit tests normal, replace the ECM

5. If all circuits test normal, perform the fuel level sensor component test before replacing the primary fuel level sensor.

Component Testing

1. Ignition OFF, remove the primary fuel level sensor.
2. While sweeping the primary fuel level sensor through its full range of motion, test for a minimum value less than 41 ohms and a maximum value greater than 119 ohms between signal terminal 4 and the low reference terminal 3.

⇒	If not within the specified range, replace the primary fuel level sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Diagnostic Instructions

DTC Descriptor

DTC P0464: Fuel Level Sensor 1 Circuit Intermittent

Diagnostic Fault Information

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
Fuel Level Sensor 1 Signal Circuit	P0462	1	P0463 P0464	P0463	P0461
Fuel Level Sensor 2 Signal Circuit	P2067	1	P2068	P2068	P2066
Fuel Level Sensor Low Reference Circuit	--	1	P0463 P2068 P0464	P0463 P2068	P0461 P2066
1. Fuel Gage Inaccurate or Inoperative

Circuit/System Description

The primary fuel level sender and the secondary fuel level sender changes resistance based on fuel level. The engine control module (ECM) monitors the signal circuits of the primary fuel level sender and the secondary fuel level sender in order to determine the fuel level. When the fuel tank is full, the resistances of both fuel level senders are low and the ECM senses a low signal voltage on both the signal circuits of the primary fuel level sender and the secondary fuel level sender. When the fuel tanks are empty, the resistances of the fuel level senders are high and the ECM senses a high signal voltage. The ECM uses the signal circuits of the primary fuel level sender and the secondary fuel level sender in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via serial data circuit to the instrument cluster in order to control the fuel gage.

This diagnostic tests for an intermittent fuel level sender signal. If a change in fuel level is detected DTC P0442 is aborted due to a possible refueling event. A refueling event test is executed to confirm that a refueling event has occurred. If refueling is confirmed, the test for DTC P0464 is considered passing. The refueling event test must pass 2 out of 3 times, otherwise, the DTC will set indicating an intermittent signal problem.

Conditions for Running the DTC

Conditions for Setting the DTC

Action Taken When the DTC Sets

Conditions for Clearing the DTC

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Instrument Cluster Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 33431-C Instrument Panel Tester

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the primary fuel level sensor.
2. Ignition OFF, test for less than 1 ohm between the primary fuel level sensor low reference circuit terminal 3 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 ECM.

3. Ignition OFF, install a signal generator and instrument panel tester between the primary fuel level sensor signal circuit terminal 4 and the low reference circuit terminal 3.
4. Ignition ON, vary the signal generator resistance between 40 and 250 ohms. Verify that the scan tool Fuel Tank Level Remaining parameter displays a range that varies between 5 and 95 percent as the signal generator resistance changes.

⇒	If not displaying the specified range, test the signal circuit terminal 1 for an open/high resistance. If the circuit tests normal, replace the ECM

5. If all circuits test normal, perform the fuel level sensor component test before replacing the primary fuel level sensor.

Component Testing

1. Ignition OFF, remove the primary fuel level sensor.
2. While sweeping the primary fuel level sensor through its full range of motion, test for a minimum value less than 41 ohms and a maximum value greater than 119 ohms between signal terminal 4 and the low reference terminal 3.

⇒	If not within the specified range, replace the primary fuel level sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.