DTC P0463 3.6L LY7

Diagnostic Instructions

DTC Descriptor

DTC P0463: Fuel Level Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Level Sensor Reference Voltage Circuit	P0462	--	--	P0461
Fuel Level Sensor Signal Circuit	P0462	P0463	P0463	P0461
Fuel Level Sensor Low Reference Circuit	--	P0463	P0463	P0461

Circuit/System Description

The fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the sensor resistance is high and the ECM senses a high signal voltage. When the fuel tank is empty, the sensor resistance is low and the ECM senses a low signal voltage. The ECM uses the signal circuit 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 serial data circuit to the instrument panel cluster (IPC). The ECM sends a serial data message to the IPC in order to display the fuel level percent on the fuel gage.

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

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

Circuit/System Verification

With the scan tool installed and the ignition ON, the Fuel Level parameter in the ECM EVAP Data List indicates a value at or greater than 4 percent.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the fuel level sensor.
2. Ignition OFF, test for less than 1 ohm of resistance between the fuel level sensor low reference circuit terminal C and ground.

⇒	If greater than the specified range, test the low reference circuit terminal C for a short to voltage or an open/high resistance. If the circuits tests normal, replace the ECM.

3. Install a 3A fused jumper wire between the fuel level sensor signal circuit terminal B and the fuel level sensor low reference circuit terminal C. Verify the Fuel Level parameter is greater than 98 percent.

⇒	If less than 98 percent, test the fuel level sensor signal circuit terminal B and low reference circuit terminal C for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

4. If all circuits test normal, perform the fuel level sensor component test before replacing either the primary or secondary fuel level sensor.

Component Testing

1. Ignition OFF, disconnect the harness connector at the fuel level sensor.
2. While sweeping the 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 of resistance between signal terminal B and the low reference terminal C.

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

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

DTC P0463 3.8L L26 and L32

Diagnostic Instructions

DTC Descriptor

DTC P0463: Fuel Level Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Level Sensor Reference Voltage Circuit	P0462	--	--	P0461
Fuel Level Sensor Signal Circuit	P0462	P0463	P0463	P0461
Fuel Level Sensor Low Reference Circuit	--	P0463	P0463	P0461

Circuit/System Description

The fuel level sensor changes resistance in response to the fuel level. The powertrain control module (PCM) monitors the signal circuit of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the sensor resistance is low and the PCM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the PCM senses a high signal voltage. The PCM uses the signal circuit of the fuel level sensor in order to calculate the percentage of fuel remaining in the tank. The PCM sends the fuel level percentage via serial data circuit to the instrument panel cluster (IPC). The PCM sends a serial data message to the IPC in order to display the fuel level in the fuel gage.

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

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

Circuit/System Verification

With the scan tool installed and the ignition ON, the Fuel Tank Level Remaining parameter in the PCM EVAP Data List indicates a value at or greater than 4 percent

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the fuel level sensor.
2. Ignition OFF, test for less than 1 ohm of resistance between the fuel level sensor low reference circuit terminal C and ground.

⇒	If greater than the specified range, test the low reference circuit terminal C for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.

3. Install a 3A fused jumper wire between the fuel level sensor signal circuit terminal B and the fuel level sensor low reference circuit terminal C. Verify the Fuel Tank Level Remaining parameter is greater than 98 percent.

⇒	If less than 98 percent, test the fuel level sensor signal terminal B and low reference circuit terminal C for a short to voltage or an open/high resistance. If the circuits test normal, replace the PCM.

4. If all circuits test normal, perform the fuel level sensor component test before replacing either the primary or secondary fuel level sensor.

Component Testing

1. Ignition OFF, disconnect the harness connector at the fuel level sensor.
2. While sweeping the 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 of resistance between signal terminal B and the low reference terminal C.

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

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.