Hummer H2. Manual — part 1648

DTC P0230

Circuit Description

The control module enables the fuel pump relay when the ignition switch is turned ON. The control module will

24

Inspect for an intermittent and for a poor connection at
the throttle body harness connector. Refer to Testing
for Intermittent Conditions and Poor Connections
and Repairing Connector Terminals in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 30

Go to Step 27

25

Inspect for an intermittent and for a poor connection at
the APP sensor harness connector. Refer to Testing for
Intermittent Conditions and Poor Connections and
Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?

-

Go to Step 30

Go to Step 28

26

Inspect for an intermittent and for a poor connection at
the TAC module harness connector. Refer to Testing
for Intermittent Conditions and Poor Connections
and Repairing Connector Terminals in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 30

Go to Step 29

27

Replace the throttle body assembly. Refer to Throttle
Body Assembly Replacement .
Did you complete the replacement?

-

Go to Step 30

-

28

Replace the APP sensor. Refer to Accelerator Pedal
Position (APP) Sensor Replacement .
Did you complete the replacement?

-

Go to Step 30

-

29

Replace the TAC module. Refer to Throttle Actuator
Control (TAC) Module Replacement .
Did you complete the replacement?

-

Go to Step 30

-

30

1. Clear the DTCs with a scan tool.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for

Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

-

Go to Step 2

Go to Step 31

31

Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?

-

Go to

Diagnostic

Trouble Code

(DTC) List

System OK

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0171/P0174 To DTC P0507 (TAC)) - 4.8L, 5.3L, and

6.0L - Hummer H2

disable the fuel pump relay within two seconds unless the control module detects ignition reference pulses. The
control module continues to enable the fuel pump relay as long as ignition reference pulses are detected. The
control module disables the fuel pump relay within two seconds if ignition reference pulses cease to be detected
and the ignition remains ON.

The control module monitors the voltage on the fuel pump relay control circuit. If the control module detects an
incorrect voltage on the fuel pump relay control circuit, a fuel pump relay control DTC sets.

Conditions for Running the DTC

z

The engine speed is more than 400 RPM.

z

The ignition voltage is between 6-18 volts.

Conditions for Setting the DTC

z

The PCM detects that the commanded state of the driver and the actual state of the control circuit do not
match.

z

The above conditions are present for a minimum of 2.5 seconds.

Action Taken When the DTC Sets

z

The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition
cycle that the diagnostic runs and fails.

z

The control module records the operating conditions at the time the diagnostic fails. The first time the
diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic
reports a failure on the second consecutive ignition cycle, the control module records the operating
conditions at the time of the failure. The control module writes the operating conditions to the Freeze
Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

z

The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles
that the diagnostic runs and does not fail.

z

A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

z

A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other
emission related diagnostic.

z

Clear the MIL and the DTC with a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

4: This step verifies that the PCM is providing voltage to the fuel pump relay.

5: This step tests for an open in the ground circuit to the fuel pump relay.

6: This step tests if the voltage is constantly being applied to the control circuit of the fuel pump relay.

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0171/P0174 To DTC P0507 (TAC)) - 4.8L, 5.3L, and

6.0L - Hummer H2

DTC P0230

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls Connector End Views or Powertrain Control
Module (PCM) Connector End Views

1

Did you perform the Diagnostic System Check-Engine
Controls?

Go to Step 2

Go to Diagnostic

System Check -

Engine Controls

2

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

2. Command the fuel pump relay ON and OFF with a

scan tool.

Does the fuel pump relay turn ON and OFF when
commanded with a scan tool?

Go to Step 3

Go to Step 4

3

1. Observe the Freeze Frame/Failure Records for this

DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for

Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 4

Go to Intermittent

Conditions

4

1. Turn OFF the ignition.

2. Remove the fuel pump relay.

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

4. Probe the control circuit of the fuel pump relay

with a test lamp that is connected to a good
ground. Refer to Probing Electrical Connectors
in Wiring Systems.

5. Command the fuel pump ON and OFF with a scan

tool.

Does the test lamp turn ON and OFF when commanded
with a scan tool?

Go to Step 5

Go to Step 6

5

1. Connect a test lamp between the control circuit of

the fuel pump relay and the ground circuit of the
fuel pump relay.

2. Command the fuel pump relay ON and OFF with a

scan tool.

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0171/P0174 To DTC P0507 (TAC)) - 4.8L, 5.3L, and

6.0L - Hummer H2

DTC P0300

Does the test lamp turn ON and OFF when commanded
with a scan tool?

Go to Step 9

Go to Step 11

6

Does the test lamp remain illuminated?

Go to Step 8

Go to Step 7

7

Test the control circuit of the fuel pump relay for a short
to ground or an open. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 14

Go to Step 10

8

Test the control circuit of the fuel pump relay for a short
to voltage. Refer to Circuit Testing and Wiring Repairs
in Wiring Systems.
Did you find and correct the condition?

Go to Step 14

Go to Step 10

9

Test for an intermittent and for a poor connection at the
fuel pump relay. 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 14

Go to Step 12

10

Test for an intermittent and for a poor connection at the
PCM. 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 14

Go to Step 13

11

Test the ground circuit of the fuel pump relay for an
open. Refer to Circuit Testing and Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

Go to Step 14

-

12

Replace the fuel pump relay.
Did you complete the replacement?

Go to Step 14

-

13

Replace the PCM. Refer to Powertrain Control Module
(PCM) Replacement .
Did you complete the replacement?

Go to Step 14

-

14

1. Clear the DTCs with a scan tool.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for

Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 15

15

Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?

Go to Diagnostic

Trouble Code

(DTC) List

System OK

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0171/P0174 To DTC P0507 (TAC)) - 4.8L, 5.3L, and

6.0L - Hummer H2