Hummer H3. Manual — part 1352

The DTC becomes history when the conditions for setting the DTC are no longer present.

The history DTC clears after 40 malfunction-free warm-up cycles.

The PCM receives the clear code command from the scan tool.

Reference Information

Fuel Level Specifications

Fuel Level Specifications

Schematic Reference

Instrument Cluster Schematics

Engine Controls Schematics

Connector End View Reference

Displays and Gages Connector End Views

Powertrain Control Module Connector End Views

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the fuel level sensor.

2. Ignition ON, verify that the scan tool Fuel Tank Level Remaining parameter is less than 4

percent.

If greater than 4 percent, test the signal circuit for a short to ground. If the circuit tests
normal, replace the PCM.

3. If all circuits test normal, test or replace the fuel level sensor.

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Displays and Gages - H3

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel Level Sensor Replacement

Control Module References for the PCM replacement, setup and programming

DTC P0463

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0463

Fuel Level Sensor Circuit High Voltage

Diagnostic Fault Information

DTC P0463

Circuit Description

The fuel level sender changes resistance based on fuel level. The powertrain control module
(PCM) monitors the signal circuit of the fuel level sender in order to determine fuel level. When
the fuel tank is full, the sender resistance is low and the PCM senses a low signal voltage. When
the fuel tank is empty, the sender resistance is high and the PCM senses a high signal voltage. The
PCM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel

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

1

P0463

P0461

Fuel Level Sensor Low
Reference Circuit

-

P0463

1

P0463

P0461

1. Fuel Gage Inaccurate or Inoperative

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Displays and Gages - H3

percentage in the tank. The PCM sends the fuel level percent via the class 2 serial data circuit to
the instrument cluster in order to control the fuel gage. The fuel level information is also used for
misfire and evaporative emission (EVAP) diagnostics.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The fuel level signal is less than 1 percent.

The above condition is present for greater than 20 seconds.

Action Taken When the DTC Sets

The fuel gage defaults to empty.

The LOW FUEL indicator illuminates.

The PCM records the operating conditions at the time the diagnostic fails. The PCM
displays the failure information in the Failure Records on the scan tool.

Conditions for Clearing the DTC

The DTC becomes history when the conditions for setting the DTC are no longer present.

The history DTC clears after 40 malfunction-free warm-up cycles.

The PCM receives the clear code command from the scan tool.

Reference Information

Fuel Level Specifications

Fuel Level Specifications

Schematic Reference

Instrument Cluster Schematics

Engine Controls Schematics

Connector End View Reference

Displays and Gages Connector End Views

Powertrain Control Module Connector End Views

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Displays and Gages - H3

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Scan Tool Data List

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 low reference circuit and

ground.

If greater than 1 ohm, test the low reference circuit for a short to voltage or an
open/high resistance. If the circuit tests normal, replace the PCM.

3. Ignition ON, install a 3-amp fused jumper between the signal circuit and the low reference

circuit. Verify the scan tool Fuel Tank Level Remaining parameter or the Fuel Level Sensor
parameter is greater than 98 percent.

If less than 98 percent, test the signal circuit for a short to voltage or an open/high
resistance. If the circuit tests normal, replace the PCM.

4. If all circuits test normal, test or replace the fuel level sensor.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel Level Sensor Replacement

Control Module References for the PCM replacement, setup and programming

DTC P0464

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

Diagnostic Procedure Instructions provides an overview of each diagnostic category.

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Displays and Gages - H3