Hummer H2. Manual - part 368

DTC P0463

Circuit Description

The fuel level sensor changes resistance in response to fuel level. The 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

4. With a scan tool, observe the Fuel Tank Level

Remaining parameter.

Does the scan tool indicate that the Fuel Tank Level
Remaining parameter is less than the specified value?

Go to

Step 5

Go to Step 4

Test the signal circuit of the fuel level sensor for a short to
ground. Refer to Circuit Testing and to Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

Go to

Step

Go to Step 7

Test the signal circuit of the fuel level sensor for a short to
ground between C106 and the fuel level sensor. Refer to
Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step

Go to Step 6

Inspect for poor connections at the harness connector of the
fuel level sensor. Refer to Testing for Intermittent
Conditions and Poor Connections and to Connector
Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step

Go to Step 8

Inspect for poor connections at the harness connector of the
PCM. Refer to Testing for Intermittent Conditions and
Poor Connections and to Connector Repairs in Wiring
Systems.
Did you find and correct the condition?

Go to

Step

Go to Step 9

Replace the fuel level sensor. Refer to Fuel Level Sensor
Replacement in Engine Controls- 6.0L (LQ4).
Did you complete the replacement?

Go to

Step

Replace the PCM. Refer to Powertrain Control Module
(PCM) Replacement in Engine Controls-6.0L (LQ4).Did
you complete the replacement?

IMPORTANT:

Program the replacement PCM.

Go to

Step

1. Use the scan tool in order to clear the DTCs.

2. Operate the vehicle within the Conditions for Running

the DTC as specified in the supporting text.

Does the DTC reset?

Go to

Step 2

System OK

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Instrument Panel, Gauges, and Console - Hummer H2

senses a high signal voltage. The PCM uses the signal circuit of the fuel level sensor in order to calculate the
percentage of remaining fuel in the tank. The PCM sends the fuel level percentage via the class 2 serial data
circuit to the instrument cluster in order to control the fuel gauge. The fuel level information is also used for
misfire and EVAP diagnostics.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

The sender output is greater than 2.9 volts.

The above condition is present for greater than 30 seconds.

Action Taken When the DTC Sets

The fuel gauge defaults to empty.

The low fuel indicator illuminates.

The PCM records the operating conditions at the time that the diagnostic test 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.

Diagnostic Aids

Use the Freeze Frame/Failure Records data in order to locate an intermittent condition. If you cannot
duplicate the DTC, the information included in the Freeze Frame/Failure Records data may help in
determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also help in
determining the number of ignition cycles that the diagnostic test reported a pass and/or fail. Operate the
vehicle within the same freeze frame conditions, including those for RPM, for engine load, for vehicle
speed, for temperature, and for others. This will isolate at what point the DTC failed.

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The number below refers to the step number on the diagnostic table.

3: Tests for the proper operation of the circuit in the low voltage range.

DTC P0463

Value

Yes

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Instrument Panel, Gauges, and Console - Hummer H2

Step

Action

(s)

Schematic Reference:Instrument Cluster Schematics

Did you perform the Instrument Cluster Diagnostic System
Check?

Go to

Step 2

Go to Diagnostic

System Check -

Instrument Cluster

1. Install a scan tool.

2. Turn the ignition ON, with the engine OFF.

3. With a scan tool, observe the Fuel Tank Level

Remaining parameter in the PCM Enhanced EVAP
data list.

Does the scan tool indicate that the Fuel Tank Level
Remaining parameter is less than the specified value?

Go to

Step 3

Go to Diagnostic

Aids

1. Turn the ignition OFF.

2. Disconnect C106.

3. Connect a 3-ampere fused jumper wire between the

signal circuit of the fuel level sensor and the low
reference circuit of the fuel level sensor on the male
terminal side of the connector.

4. Turn the ignition ON, with the engine OFF.

5. With a scan tool, clear the DTCs.

6. With a scan tool, observe the Fuel Tank Level

Remaining parameter.

Does the scan tool indicate that the Fuel Tank Level
Remaining parameter is greater than the specified value?

98%

Go to

Step 6

Go to Step 4

Test the signal circuit of the fuel level sensor for an open, for
a high resistance, or for a short to voltage. Refer to Circuit
Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step

Go to Step 5

Test the low reference circuit of the fuel level sensor for an
open, for a high resistance, or for a short to voltage. Refer to
Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step

Go to Step 9

Test the signal circuit of the fuel level sensor for an open, for
a high resistance, or for a short to voltage between C106 and
the fuel level sensor. Refer to Circuit Testing and to Wiring
Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step

Go to Step 7

Test the low reference circuit of the fuel level sensor for an
open, for a high resistance, or for a short to voltage between
C106 and the fuel level sensor. Refer to Circuit Testing and
to Wiring Repairs in Wiring Systems.

Go to

Step

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Instrument Panel, Gauges, and Console - Hummer H2

DTC P0522

Circuit Description

The engine oil pressure (EOP) sensor changes resistance based on engine oil pressure. The PCM monitors the
signal circuit of the EOP sensor. When the oil pressure is high, the sensor resistance is high, and the PCM
senses a high signal voltage. When the oil pressure is low, the sensor resistance is low, and the PCM senses a
low signal voltage. The PCM sends the engine oil pressure information to the IPC via the class 2 serial data
circuit.

Conditions for Running the DTC

The engine is running.

DTC P0641 is not present.

Conditions for Setting the DTC

The PCM detects that the EOP sensor signal circuit is less than 0.4 volts.

The above condition is present for greater than 9 seconds.

Did you find and correct the condition?

Go to Step 8

Go to

Step

Go to Step 10

Go to

Step

Go to Step 11

Replace the fuel level sensor. Refer to Fuel Level Sensor
Replacement in Engine Controls- 6.0L (LQ4).
Did you complete the replacement?

Go to

Step

Replace the PCM. Refer to Powertrain Control Module
(PCM) Replacement in Engine Controls- 6.0L (LQ4).Did
you complete the replacement?

IMPORTANT:

Program the replacement PCM.

Go to

Step

1. Use the scan tool in order to clear the DTCs.

2. Operate the vehicle within the Conditions for Running

the DTC as specified in the supporting text.

Does the DTC reset?

Go to

Step 2

System OK

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Instrument Panel, Gauges, and Console - Hummer H2

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