Hummer H2. Manual — part 1126

STARTER SOLENOID CLICKS, ENGINE DOES NOT CRANK

Starter Solenoid Clicks, Engine Does Not Crank

ENGINE CRANKS SLOWLY

Perform the following checks:

z

Battery - Battery Inspection/Test. Refer to Battery Inspection/Test (Non-HP2) .

26

Switch Replacement in Automatic Transmission - 4L60-
E/4L65-E.
Did you complete the replacement?

Go to Step 29

-

27

Replace the ignition switch. Refer to Ignition Switch
Replacement in Steering Wheel and Column.
Did you complete the replacement?

Go to Step 29

-

28

Replace the starter. Refer to Starter Motor Replacement .
Did you complete the replacement?

Go to Step 29

-

29

Operate the system for which the symptom occurred.
Did you correct the condition?

System OK

Go to Step 2

Step

Action

Yes

No

Schematic Reference: Starting and Charging Schematics

1

Did you perform the Engine Electrical Diagnostic System
Check?

Go to

Step 2

Diagnostic System Check

- Engine Electrical

2

Turn the ignition to the START position.
Did the starter solenoid click?

Go to

Step 3

Go to Starter Solenoid

Does Not Click

3

Inspect the engine and belt drive system for mechanical
binding (seized engine, seized generator).
Does the engine move freely?

Go to

Step 4

Go to Symptoms - Engine

Mechanical in Engine

Mechanical.

4

Test the battery positive cable between the battery and the
starter solenoid for high resistance. Refer to Circuit Testing
and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step 8

Go to Step 5

5

Test the ground circuit between the battery and the starter
motor for a high resistance. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to

Step 8

Go to Step 6

6

Inspect for poor connections at the starter. 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 8

Go to Step 7

7

Replace the Starter. Refer to Starter Motor Replacement .
Did you complete the replacement?

Go to

Step 8

-

8

Operate the system for which the symptom occurred.
Did you correct the condition?

System

OK

Go to Step 2

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

z

Wiring - Inspect the wiring for damage. Inspect all connections to the starter motor, solenoid, battery, and
all ground connections. Refer to Circuit Testing , Wiring Repairs , Testing for Intermittent
Conditions and Poor Connections and Connector Repairs in Wiring Systems.

z

Engine - Make sure the engine is not seized. Refer to Symptoms - Engine Mechanical in Engine
Mechanical.

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 .

STARTER MOTOR NOISE DIAGNOSIS

Diagnostic Aids

z

Inspect the flywheel ring gear for damage or unusual wear.

z

Shim the starter if applicable.

z

In order to add pinion to ring gear clearance a full size shim must be used. Do not shim only 1 starter
mounting bolt. There are 3 shims available in different shapes for clearance. All are 1 mm (0.039 in)
thick.

Starter Motor Noise Diagnosis

Step

Action

Yes

No

1

Did you perform the Engine Electrical Diagnostic
System Check?

Go to Step 2

Go to Diagnostic

System Check -

Engine Electrical

2

Start the engine.
Does the starter operate normally?

Go to Testing for

Intermittent Conditions

and Poor Connections in

Wiring Systems

Go to Step 3

3

Start the engine while listening to the starter motor
turn.
Is there a loud "whoop", it may sound like a siren if
the engine is revved while the starter is engaged
after the engine starts, but while the starter is still
held in the engaged position?

Go to Step 6

Go to Step 4

4

Do you hear a "rumble", a "growl", or, in some
cases, a "knock" as the starter is coasting down to a
stop after starting the engine?

Go to Step 7

Go to Step 5

5

This is often diagnosed as a starter drive gear hang-
in or a weak solenoid.
When the engine is cranked, do you hear a high-
pitched whine after the engine cranks and starts
normally?

Go to Step 8

Go to Step 7

Inspect the flywheel ring gear for the following:

z

Chipped gear teeth

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

REPAIR INSTRUCTIONS

BATTERY NEGATIVE CABLE DISCONNECT/CONNECT PROCEDURE (SINGLE BATTERY)

Removal Procedure

1. Turn off all the lamps and accessories.

2. Turn the ignition OFF.

6

z

Missing gear teeth

z

Milled teeth

Is the flywheel bent, or does it have damaged
teeth?

Go to Step 9

Go to Step 10

7

1. Remove the starter motor. Refer to Starter

Motor Replacement .

2. Inspect the starter motor bushings and clutch

gear.

Does the clutch gear have chipped or milled teeth
or worn bushings?

Go to Step 10

Go to Step 9

8

Shim the starter motor away from the flywheel by
adding shims between the starter motor and the
engine block one at a time.
Flywheel runout may make this noise appear to be
intermittent.
Did you complete the repair?

Go to Step 11

-

9

Replace the flywheel. Refer to Engine Flywheel
Replacement in Engine Mechanical.
Did you complete the replacement?

Go to Step 11

-

10

Replace the starter motor. Refer to Starter Motor
Replacement .
Did you complete the replacement?

Go to Step 11

-

11

Operate the system in order to verify the repair.
Did you correct the condition?

System OK

Go to Step 3

CAUTION: Refer to Battery Disconnect Caution in Cautions and Notices.

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

Fig. 7: Battery Ground Negative Cable & Bolt
Courtesy of GENERAL MOTORS CORP.

3. Remove the battery ground negative cable and bolt from the battery.

Installation Procedure

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2