Hummer H2. Manual — part 1145

A. Disconnect the negative battery cable.

B. Disconnect the positive battery cable.

C. Install the tester adapters.

D.

Follow the instructions for testing a removed battery.

E. Replace the battery only if the second test shows a REPLACE BATTERY or BAD CELL-

REPLACE result. Use the test code from the second test for any warranty purposes.

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Use the correct terminal adapters. Do not use any common bolts or a combination of bolts, of nuts, and of
washers as adapters when testing the battery. Use the test adapters that are provided with the J-42000 or
GM P/N 12303040 terminal adapters. If the adapters that are provided with the J-42000 require
replacement, use GM P/N 12303040. Any other adapter may not contact the correct areas of the battery
terminal, causing a resistance that may result in an invalid battery test result.

Diagnostic Procedures

1. Inspect the battery for a cracked, broken, or damaged case, which may be indicated by battery acid

leakage. Is the battery OK? If yes, go to next step. If no, go to step 19 .

2. Compare the Cold Cranking Amperage (CCA) and Reserve Capacity (RC) of the battery to the original

battery or Original Equipment (OE) specification. Refer to BATTERY USAGE . Does the battery meet
or exceed the specifications? If yes, go to next step. If no, go to step 19 .

3. Does the hydrometer display a yellow dot? If yes, go to next step. If no, go to step 5 .

4. Tap the hydrometer lightly on top with the handle of a small screwdriver in order to dislodge any air

bubbles inside the battery. Does the hydrometer still display a yellow dot? If yes, go to step 19 . If no, go
to next step.

5. Turn OFF the ignition. Attempt to rotate the negative battery cable connector clockwise with light finger

pressure. Does the negative connector rotate? If yes, go to next step. If no, go to step 7 .

6. Use a torque wrench in order to verify the torque to loosen the negative battery terminal bolt. Is the torque

above the specified value? 10 N.m (88 lb in). If yes, go to step 8 . If no, go to next step.

NOTE:

Important: Always write the test code displayed by the tester on the
repair order for any warranty purposes. The number is a unique code
that describes the test data for a particular battery at a particular
time. The test code may occasionally repeat when you retest the
same battery. More often, each test will result in a different code. Use
the test code from the second, or Out of Vehicle test.

CAUTION: Before servicing any electrical component, the ignition key must be in the

OFF or LOCK position and all electrical loads must be OFF, unless
instructed otherwise in these procedures. If a tool or equipment could
easily come in contact with a live exposed electrical terminal, also
disconnect the negative battery cable. Failure to follow these precautions
may cause personal injury and/or damage to the vehicle or its
components.

2004 Hummer H2

2004 STARTING & CHARGING SYSTEMS Starters - H2

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:

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Scan tool power battery positive voltage at terminal 16.

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Scan tool power ground at terminal 4.

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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