Hummer H2. Manual — part 367

DTC P0461

Circuit Description

3

2. Observe the Battery Voltage parameter in the BCM Data

list.

3. Turn the ignition OFF.

Does the Battery Voltage parameter display Active with the
ignition off?

Go to

Step 8

Go to Step 7

4

Test the key in ignition signal circuit for an open or a high
resistance. Refer to Circuit Testing and Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

Go to

Step

11

Go to Step 5

5

Test the ground circuit of the ignition key alarm switch for an
open or a high resistance. Refer to Circuit Testing and Wiring
Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step

11

Go to Step 6

6

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

Go to

Step

11

Go to Step 9

7

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

Go to

Step

11

Go to Step 10

8

Repair the short to voltage in the ignition 1 voltage circuit. Refer
to Wiring Repairs in Wiring Systems.
Did you correct the condition?

Go to

Step

11

-

9

Replace the ignition switch. Refer to Ignition Switch
Replacement in Steering Wheel and Column.
Did you complete the replacement?

Go to

Step

11

-

10

Replace the BCM. Refer to Body Control Module Replacement
in Body Control System.Did you complete the replacement?

IMPORTANT:

Perform the set up procedure for the replacement BCM.

Go to

Step

11

-

11

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

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 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 evaporative emission (EVAP) diagnostics.

This diagnostic tests for a stuck fuel level sensor signal. The PCM sets this DTC if the fuel level sensor signal
appears to be stuck based on a lack of signal variation expected during normal operation.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

The PCM does not detect a change in fuel level of at least 3.0L (0.79 gal) over a distance of 320 km (200
miles).

Action Taken When the DTC Sets

z

The fuel gauge defaults to empty.

z

The low fuel indicator illuminates.

z

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

z

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

z

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

z

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

Diagnostic Aids

z

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.

z

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

DTC P0461

Step

Action

Yes

No

Schematic Reference:Instrument Cluster Schematics

2004 Hummer H2

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

DTC P0462

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
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

z

The sender output is less than 0.39 volts.

z

The above condition is present for greater than 30 seconds.

Action Taken When the DTC Sets

z

The fuel gauge defaults to empty.

z

The low fuel indicator illuminates.

1

Did you perform the Diagnostic System Check -
Instrument Cluster?

Go to

Step 2

Go to Diagnostic System

Check - Instrument Cluster

2

1. Remove the fuel level sender.

2. Inspect for the following items:

z

The fuel level sensor is stuck, perhaps due to
an interference with the fuel strainer.

z

The fuel tank contains foreign material, for
instance, ice.

Did you find and correct the condition?

Go to

Step 4

Go to Step 3

3

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 4

-

4

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

z

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

z

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

z

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

z

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

Diagnostic Aids

z

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.

z

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 high voltage range.

DTC P0462

Step

Action

Value

(s)

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the Instrument Cluster Diagnostic System
Check?

-

Go to

Step 2

Go to Diagnostic

System Check -

Instrument Cluster

2

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 greater than the specified value?

98%

Go to

Step 3 Go to Diagnostic Aids

1. Turn the ignition OFF.

2. Disconnect C106.

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

2004 Hummer H2

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