Hummer H2. Manual — part 1913

If the battery, the wiring and the engine are functioning properly and the engine continues to crank slowly,
replace the starter motor. Refer to STARTER MOTOR REPLACEMENT .

BATTERY INSPECTION/TEST (NON-HP2)

Diagnostic Aids

Follow these instructions in order to avoid an incorrect diagnosis because of connections:

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If testing the vehicle with the battery cables still connected, wiggle the J-42000 clips on the terminal bolt.
This may cut through any coating or through any oxidation that may be present on the bolt. Even new
bolts contain a protective coating that may insulate or cause a resistance in the test circuit.

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If correct connections to the battery terminal bolts in the vehicle are in doubt, perform the following
steps:

1. Disconnect the negative battery cable.

2. Disconnect the positive battery cable.

3. Install the test adapters on the terminals.

4. Follow the instructions for testing a removed battery.

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If the tester displays a REPLACE BATTERY or BAD CELL-REPLACE result for a battery tested in the
vehicle with the battery cables connected, perform the following steps:

1. Disconnect the negative battery cable.

2. Disconnect the positive battery cable.

3. Install the test adapters on the terminals.

4.

Follow the instructions for testing a removed battery.

5. 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

NOTE:

The battery test using the J-42000 Battery Tester requires correct connections
to the battery terminals. A failure to obtain the correct connections during the
test may result in a failed test on a good battery. Use the Out of Vehicle test for
each battery when testing a vehicle with dual batteries.

NOTE:

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.

2004 Hummer H2

2004 STARTING & CHARGING SYSTEMS Starters - H2

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

7. Disconnect the negative battery cable. Is the cable disconnected? If yes, go to step 9 .

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. Is the repair complete? If yes, 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 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 .

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 .

NOTE:

Ensure that all of the electrical loads are turned OFF.

2004 Hummer H2

2004 STARTING & CHARGING SYSTEMS Starters - H2

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

order. Did you complete this action? If yes, battery OK.

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 .

CHARGE INDICATOR ALWAYS ON

1. Did you perform the Engine Electrical Diagnostic System Check? If yes, go to next step. If no, go to

DIAGNOSTIC SYSTEM CHECK - ENGINE ELECTRICAL .

2. Turn ON the ignition, with the engine OFF. Observe the Charge indicator on the instrument cluster (IPC).

Does the charge indicator illuminate? If yes, go to next step. If no, go to SYMPTOM LIST .

3. Turn OFF the ignition. Disconnect the generator connector. Turn ON the ignition, with the engine OFF.

Does the charge indicator illuminate? If yes, go to next step. If no, go to Charging System Test in
GENERATORS & REGULATORS .

4. Test the charge indicator control circuit for a short to ground. Did you find and correct the condition? If

yes, go to step 6 . If no, go to next step.

5.

Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement. Is the action complete? If
yes, go to next step.

6. Operate the system in order to verify the repair. Did you correct the condition? If yes, system OK. If no,

go to step 2 .

CHARGE INDICATOR INOPERATIVE

1. Did you perform the Diagnostic System Check for Starting and Charging? If yes, go to next step. If no,

go to Diagnostic System Check in Engine Electrical.

2. Turn ON the ignition, with the engine OFF. Does the battery charge indicator illuminate during the bulb

check? Problem is intermittent. If yes, go to next step.

3. Replace the charge indicator bulb. Did you complete the replacement? If yes, go to next step.

4. Operate the system in order to verify the repair. Did you correct the condition? If yes, system OK. If no,

go to step 2 .

CHARGING SYSTEM TEST (CS/AD/SI GENERATORS)

1. Did you perform the Engine Electrical Diagnostic System Check? If yes, go to next step. If no, go to

Diagnostic System Check in Engine Electrical.

2. Start the engine. Observe the charge indicator on the instrument cluster (IPC). Does the charge indicator

illuminate or message center (DIC) display a charging system message? If yes, go to next step. If no, go
to Symptoms in Engine Electrical.

3.

NOTE:

The replacement PCM must be programmed.

2004 Hummer H2

2004 STARTING & CHARGING SYSTEMS Starters - H2

Turn OFF the ignition. Connect the red lead of the J-41450-B Universal CS Generator Test Harness to the
generator output terminal. Connect the black lead of the J-41450-B to the metal generator housing. Does
the green POWER lamp on the tester illuminate? If yes, go to step 6 . If no, go to next step.

4. Measure the voltage from the output terminal of the generator to the generator metal housing. Does the

voltage measure equal to the specified value? 12.0 V. If yes, go to step 14 . If no, go to next step.

5. Measure the voltage from the output terminal of the generator to the battery negative terminal. Does the

voltage measure equal to the specified value? 12.0 V. If yes, go to step 12 . If no, go to step 11 .

6.

Turn OFF completely the load tool before connecting or disconnecting a carbon pile load tester to the
battery. Otherwise, sparking at the terminals could cause battery gasses to explode. Connect a carbon pile
tester to the vehicle. Connect an inductive ammeter to the output circuit of the generator. Disconnect the
generator harness connector. Locate the matching harness connector on the J-41450-B , and connect the
connector to the generator. Does the red DIAGNOSTIC lamp on the tester illuminate? If yes, go to next
step. If no, go to step 13 .

7. Start the engine and allow it to idle for 30 seconds. Increase the engine speed to 2,500 RPM. Does the red

DIAGNOSTIC lamp on the tester illuminate? If yes, go to step 15 . If no, go to next step.

8.

Maintain the engine speed at 2,500 RPM. Turn ON the load of the carbon pile tester and increase the load
until the generator output is equal to the Load Test value given in Generator Usage. See GENERATORS
& REGULATORS . Does the red DIAGNOSTIC lamp on the tester illuminate? If yes, go to step 15 . If
no, go to next step.

9. Maintain the engine speed at 2,500 RPM and continue to operate the generator at the load test value.

Measure the voltage drop from the output terminal of the generator to the positive terminal on the battery.
Does the voltage measure greater than the specified value? 0.5 V. If yes, go to step 11 . If no, go to next
step.

10. Maintain the engine speed at 2,500 RPM and continue to operate the generator at the load test value.

Measure the voltage drop from the battery negative terminal to the metal housing of the generator. Does
the voltage measure greater than the specified value? 0.5 V. If yes, go to step 12 . If no, go to step 16 .

11. Repair the high resistance or an open in the output circuit of the generator. Did you complete the repair?

If yes, go to step 16 .

12. Repair the high resistance or open in the ground circuit of the generator. Did you complete the repair? If

yes, go to step 16 .

13. Disconnect the J-41450-B tester harness connector from the generator, but leave the alligator clips

connected so that the green POWER lamp remains illuminated. Connect a jumper lead, with an in-line
100-ohm resistor between the J-41450-B tester harness connector terminal B of the generator and a good

NOTE:

The green POWER lamp of the tester should remain illuminated while the
tester is being used.

NOTE:

Ensure that all generator output circuit wires pass through the inductive
probe.

NOTE:

If the generator is not capable of producing the Load Test amps, operate
the generator at it's maximum possible output.

2004 Hummer H2

2004 STARTING & CHARGING SYSTEMS Starters - H2