Content .. 1648 1649 1650 1651 ..

Hummer H2. Manual - part 1650

in Engine

Mechanical - 4.8L,

5.3L and 6.0L

Go to Step 13

13 Is the spark plug gas fouled?

Go to Step 16

Go to Step 14

Did the spark plug show any signs of being
cracked, worn, or improperly gapped?

Go to Step 17

Go to Step 15

Perform the fuel injector coil test. Refer to Fuel
Injector Coil Test .
Did you find and correct the condition?

Go to Step 20

Go to Symptoms -

Engine Mechanical

in Engine

Mechanical - 4.8L,

5.3L and 6.0L

Perform the fuel system diagnosis. Refer to Fuel
System Diagnosis .
Did you find and correct the condition?

Go to Step 20

Go to Symptoms -

Engine Mechanical

in Engine

Mechanical - 4.8L,

5.3L and 6.0L

Replace or gap the spark plug. Refer to Spark
Plug Replacement .
Did you complete the action?

Go to Step 20

Replace the faulty spark plug. Refer to Spark
Plug Replacement .
Did you complete the replacement?

Go to Step 20

Replace the faulty spark plug wires. Refer to
Spark Plug Wire Replacement .
Did you complete the replacement?

Go to Step 20

Was the customer concern the malfunction
indicator lamp (MIL) flashing?

Go to Step 21

Go to Step 22

1. Operate the vehicle at the specified value

for 4 minutes.

2. Operate the vehicle within the Conditions

for Running the DTC P0420 or P0430 as
specified in the supporting text. Refer to
DTC P0420 or P0430 .

Does the DTC run and pass?

2,500

RPM

Go to Step 22

Go to DTC P0420

or P0430

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.

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 P0315

Circuit Description

The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused
by slight tolerance variations in the crankshaft, and the CKP sensor. The calculated error allows the powertrain
control module (PCM) to accurately compensate for reference period variations. This enhances the ability of the
PCM to detect misfire events over a wide range of engine speed and load. The PCM stores the Crankshaft
Position System Variation values after a learn procedure has been performed. If the actual crankshaft position
variation is not within the Crankshaft Position System Variation compensating values stored in the PCM, DTC
P0300 may set. If the CKP system variation values are not stored in the PCM memory, DTC P0315 sets.

Conditions for Running the DTC

DTCs P0335, P0336, P0341, P0342, or P0343 are not set.

Conditions for Setting the DTC

The CKP system variation values are not stored in the PCM memory.

Action Taken When the DTC Sets

The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

The control module records the operating conditions at the time the diagnostic fails. The control module
stores this information in the Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

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

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

Clear the MIL and the DTC with a scan tool.

DTC P0315

Did the DTC fail this ignition?

Go to Step 2

Go to Step 23

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

Step

Action

Yes

Did you perform the Diagnostic System Check -
Engine Controls?

Go to Step 2

Go to Diagnostic

System Check -

Engine Controls

Preform the crankshaft position (CKP) system
variation learn procedure. Refer to CKP System

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 P0325

Circuit Description

The knock sensors (KS) produce an AC signal under all engine operating conditions. When the engine is
running, the powertrain control module (PCM) learns a minimum and maximum frequency of normal engine
noise. The KS system monitors both knock sensors in order to determine if knock is present. If the KS system

Variation Learn Procedure .
Does the scan tool display Learned this ignition?

Go to Step 4

Go to Step 3

If the CKP system variation learn procedure cannot
be performed successfully, check for the following
conditions and correct as necessary:

Worn crankshaft main bearings

A damaged reluctor wheel

Excessive crankshaft runout

A damaged crankshaft

Interference in the signal circuit of the CKP
sensor

Any foreign material passing between the CKP
sensor and the reluctor wheel

A coolant temperature that is not within the
Conditions For Running the DTC

The ignition switch is in the ON position until
the battery is drained.

A powertrain control module (PCM) power
disconnect with the ignition ON may erase the
stored value and set the DTC P0315.

Did you complete the inspection?

Go to Step 4

1. Clear the DTCs with a scan tool.

2. Turn OFF the ignition.

3. Start the engine.

4. Operate the vehicle within the Conditions for

Running the DTC as specified in the
supporting text.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 5

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

determines that excessive knock is present, the PCM retards the spark timing based on the signals from the KS.
The PCM continues to retard timing until no knock is present. If the PCM malfunctions in a manner that will
not allow proper diagnosis of the KS system this DTC will set

Conditions for Running the DTC

The engine run time is more than 10 seconds.

The ignition voltage is more than 10 volts.

Conditions for Setting the DTC

The PCM malfunctions in a manner that will not allow proper diagnosis of the KS system.

The above condition is present for 12 seconds.

Action Taken When the DTC Sets

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

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

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

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

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

Clear the MIL and the DTC with a scan tool.

DTC P0325

Step

Action

Yes

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

Did you perform the Diagnostic System Check-Engine
Controls?

Go to Step 2

Go to Diagnostic

System Check -

Engine Controls

1. Observe the Freeze Frame/Failure Records for this

DTC.

2. Turn OFF the ignition for 30 seconds.

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

Content .. 1648 1649 1650 1651 ..