Hummer H2. Manual - part 1909

 

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Hummer H2. Manual - part 1909

 

 

7. Disconnect the negative battery cable. Is the cable disconnected? If yes, go to step 9 . If no, go to next 

step.  

8. Disconnect the negative battery cable. Inspect for the following conditions and repair as needed: The 

cable bolt is too long or deformed at the end. There is foreign material present inside the nut in the battery 
terminal. Damage to the battery terminal face or cable connector ring. After repairs, go to next step.  

9. Rotate the positive battery cable connector clockwise with light finger pressure. Does the positive 

connector rotate? If yes, go to next step. If no, go to step 11 .  

10. Use a torque wrench in order to verify the torque to loosen the positive battery terminal bolt. Is the torque 

above the specified value? 10 N.m (88 lb in). If yes, go to step 12 . If no, go to next step.  

11. Disconnect the positive battery cable. Is the cable disconnected? If yes, go to step 13 . If no, go to next 

step.  

12. Disconnect the positive battery cable. Inspect for the following conditions and repair as needed: The cable 

bolt is too long or deformed at the end. There is foreign material present inside the nut in the battery 
terminal. Damage to the battery terminal face or cable connector ring. After repairs, go to next step.  

13. Clean and wire brush the lead face of both battery terminals and the metal contact rings in both cable 

connectors. Remove the bolts from the cable connectors in order to provide access to the connector rings 
as needed. If either of the battery terminals or the cable rings are excessively damaged or corroded, 
replace as needed. Are the metal connecting parts clean and in good condition? If yes, go to next step.  

14. Connect the positive battery cable to the battery positive terminal. Tighten the cable bolt to the specified 

value. Is the cable bolt properly tightened? 15 N.m (11 lb ft). If yes, go to next step.  

15. Connect the negative battery cable to the battery negative terminal. Tighten the cable bolt to the specified 

value. Is the cable bolt properly tightened? 15 N.m (11 lb ft). If yes, go to next step.  

16.  

Install the J-42000 Battery Tester. Follow the directions supplied with the tester. Follow any direction 
displayed on the tester. Did the tester pass the battery? If yes, go to next step. If no, go to step 18 .  

17. Press the CODE button on the J-42000. For warranty purposes, write the displayed code on the repair 

order.  

18. Press the CODE button on the J-42000. For warranty purposes, write the displayed code on the repair 

order. Replace the battery. Refer to BATTERY REPLACEMENT .  

19. Replace the battery. Refer to BATTERY REPLACEMENT .  

SCAN TOOL DOES NOT POWER UP 

Circuit Description 

The data link connector (DLC) is a standardized 16 cavity connector. Connector design and location is dictated 
by an industry wide standard, and is required to provide the following:  

z

Scan tool power battery positive voltage at terminal 16.  

z

Scan tool power ground at terminal 4.  

z

Common signal ground at terminal 5. 

NOTE:

Ensure that all of the electrical loads are turned OFF. 

 

2004 Hummer H2 

2004 STARTING & CHARGING SYSTEMS Starters - H2

  

The scan tool will power up with the ignition OFF. Some modules however, will not communicate unless the 
ignition is ON and the power mode master (PMM) module sends the appropriate power mode message.  

Test Description 

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

4 - If the battery positive voltage and ground circuits of the DLC are functioning properly. The 
malfunction must be due to the scan tool.  

Diagnostic Procedures 

1. Test the battery positive voltage circuit of the data link connector (DLC) for an open or a short to ground. 

Did you find and correct the condition? If yes, go to Body Control Module for the applicable Diagnostic 
System Check. If no, go to next step.  

2. Test the ground circuit from pin 4 of the DLC for an open or high resistance. Did you find and correct the 

condition? If yes, go to Body Control Module for the applicable Diagnostic System Check. If no, go to 
next step.  

3. Inspect for poor connections and terminal tension at the DLC. Did you find and correct the condition? If 

yes, go to Body Control Module for the applicable Diagnostic System Check. If no, go to next step.  

4. The scan tool may be malfunctioning. Refer to the scan tool user guide. Did you obtain a properly 

operating scan tool? If yes, go to Body Control Module for the applicable Diagnostic System Check.  

POWER MODE MISMATCH 

Circuit Description 

Normal vehicle class 2 communications and module operations will not begin until the system power mode has 
been identified. Discrete wires from the ignition switch contacts are monitored by the power mode master 
(PMM) module in order to determine the correct power mode. The PMM communicates the system power 
mode to all class 2 modules on the class 2 serial data line. Refer to appropriate BODY CONTROL MODULE 
article for System Description and Operation to identify which module is the PMM and the applicable power 
mode look up table.  

Test Description 

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

6 - This step tests for battery voltage on the signal circuits that are not required.  

7 - This step tests for no battery voltage on the required signal circuits.  

8 - If any ignition switch parameters that should be inactive in the present ignition switch position are 
active, 2 ignition switch signal circuits may be shorted together.  

9 - This step eliminates open circuits as the cause of the malfunction.  

Diagnostic Procedures 

 

2004 Hummer H2 

2004 STARTING & CHARGING SYSTEMS Starters - H2

  

1. Install a scan tool. Turn OFF the ignition. With a scan tool, under the Diagnostic Circuit Check menu 

observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the actual 
ignition switch position? If yes, go to next step. If no, go to step 6 .  

2. Turn the ignition switch to the UNLOCK position. With a scan tool, under the Diagnostic Circuit Check 

menu observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the 
actual ignition switch position? If yes, go to next step. If no, go to step 6 .  

3. Turn ON the ignition, with the engine OFF. With a scan tool, under the Diagnostic Circuit Check menu 

observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the actual 
ignition switch position? If yes, go to next step. If no, go to step 6 .  

4.  

Turn the ignition switch to the CRANK position. With a scan tool, under the Diagnostic Circuit Check 
menu observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the 
actual ignition switch position? If yes, go to next step. If no, go to step 6 .  

5. Turn the ignition switch to the ACCY position. With a scan tool, under the Diagnostic Circuit Check 

menu observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the 
actual ignition switch position? If yes, problem is intermittent. If no, go to next step.  

6.  

Turn OFF the ignition. Disconnect the PMM. Hold the ignition switch in the position that indicated the 
incorrect power mode. With a test lamp attached to a good ground, test the PMM ignition switch inputs 
for voltage. Is voltage present on only the inputs specified for the ignition switch position? If yes, go to 
next step. If no, go to step 8 .  

7.  

Hold the ignition switch in the position that indicated the incorrect power mode. With a test lamp 
attached to a good ground, test the PMM ignition switch inputs for voltage. Refer to Body Control 
Module. Is voltage not present on any inputs specified for the ignition switch position? If yes, go to step 
9 . If no, go to step 11 .  

8. Disconnect the ignition switch. Test the PMM ignition switch input circuits for a short to voltage. Test the 

PMM ignition switch circuits for a short between circuits. Did you find and correct the condition? If yes, 

NOTE:

This table is used if the observed vehicle power mode does not match the 
ignition switch position. 

NOTE:

Open the driver door and leave it open during this test. This will disable the 
RAP power mode and eliminate this power mode from the power mode 
parameter list. 

NOTE:

The engine may start during this procedure. Turn the ignition OFF after 
verifying this power mode. 

NOTE:

The engine may start during this procedure. Turn the ignition OFF after 
verifying this power mode. 

NOTE:

The engine may start during this procedure. Turn the ignition OFF after 
verifying this power mode. 

 

2004 Hummer H2 

2004 STARTING & CHARGING SYSTEMS Starters - H2

  

go to step 14 . If no, go to step 10 .  

9. Disconnect the ignition switch. Test the PMM ignition switch input circuits for an open. Did you find and 

correct the condition? If yes, go to step 14 . If no, go to next step.  

10. Inspect for poor connections and terminal tension at the harness connector of the ignition switch. Did you 

find and correct the condition? If yes, go to step 14 . If no, go to step 12 .  

11. Inspect for poor connections and terminal tension at the harness connector of the PMM. Did you find and 

correct the condition? If yes, go to step 14 . If no, go to step 13 .  

12. Replace the ignition switch. After repairs, go to step 14 .  

13.  

Replace the PMM. After replacement, go to next step.  

14.  

Reconnect all disconnected components. With a scan tool, under the Diagnostic Circuit Check menu 
observe the Class 2 Power Mode parameter. Cycle the ignition switch through all possible positions one 
at a time. Does the displayed power mode parameter match the actual ignition switch position? If yes, 
system OK. If no, go to step 1 .  

SCAN TOOL DATA LIST 

Scan Tool Data List 

SCAN TOOL DATA DEFINITIONS 

Ignition 1 Signal - The scan tool displays the current voltage at the battery.  

GEN L-Terminal Signal Command - The scan tool displays OK/No Output. The scan tool displays OK 
until malfunction is detected on the generator L-terminal circuit, then it reads No Output.  

GEN F-Terminal Signal - The scan tool displays 0-100%. The scan tool displays 0-5% until the engine 
is running, then the percentage value varies depending on electrical loads. 

NOTE:

After replacement of the PMM perform the programming or set up 
procedure if required. 

NOTE:

The engine may start during this procedure. Turn the ignition OFF after 
verifying all power modes. 

Scan Tool Parameter 

Data List 

Units 

Displayed 

Typical Data 

Value 

Ignition On, With Engine Off 

Ignition 1 Signal 

Engine 1,2 

Data 

Volts 

9-14 volts 

GEN L-Terminal Signal 
Command 

Engine 2 Data  OK/No Output 

OK 

GEN F-Terminal Signal 

Engine 2 Data 

10-90% 

 

2004 Hummer H2 

2004 STARTING & CHARGING SYSTEMS Starters - H2

  

 

 

 

 

 

 

 

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