Hummer H3. Manual — part 1138

ENGINE CRANKS SLOWLY

Perform the following checks:

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

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 .

Engine-Make sure the engine is not seized.

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

Inspect the flywheel ring gear for damage or unusual wear.

Starter Motor Noise Diagnosis

5

Refer to Circuit Testing and Wiring
Repairs .
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 .
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

Step

Action

Yes

No

1

Did you perform the Diagnostic System
Check - Vehicle?

Go to
Diagnostic
System Check -

2007 Hummer H3

2007 ENGINE Engine Electrical - H3

Go to Step 2 Vehicle

2

Start the engine.
Does the starter operate normally?

Go to Testing
for Intermittent
Conditions and
Poor
Connections

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 6

Go to Step 7

6

Inspect the flywheel ring gear for the
following:

Chipped gear teeth

Missing gear teeth

Milled teeth

Is the flywheel bent or does it have
damaged teeth?

Go to Step 8

Go to Step 9

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

2007 Hummer H3

2007 ENGINE Engine Electrical - H3

REPAIR INSTRUCTIONS

BATTERY NEGATIVE CABLE DISCONNECTION AND CONNECTION

Disconnecting Procedure

milled teeth or worn bushings?

Go to Step 9

Go to Step 8

8

Replace the flywheel. Refer to Engine
Flywheel Replacement (w/Automatic
Transmission) .
Did you complete the replacement?

Go to Step 10

-

9

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

Go to Step 10

-

10

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

System OK

Go to Step 3

CAUTION: Batteries produce explosive gases. Batteries contain

corrosive acid. Batteries supply levels of electrical current
high enough to cause burns. Therefore, in order to reduce the
risk of personal injury while working near a battery, observe
the following guidelines:

Always shield your eyes.

Avoid leaning over the battery whenever possible.

Do not expose the battery to open flames or sparks.

Do not allow battery acid to contact the eyes or the skin.

Flush any contacted areas with water immediately
and thoroughly.

Get medical help.

CAUTION: Unless directed otherwise, the ignition and start switch must

be in the OFF or LOCK position and all electrical loads must
be OFF before servicing any electrical component. Disconnect
the negative battery cable to prevent an electrical spark
should a tool or equipment come in contact with an exposed
electrical terminal. Failure to follow these precautions may

2007 Hummer H3

2007 ENGINE Engine Electrical - H3

Fig. 11: Identifying Battery Cables
Courtesy of GENERAL MOTORS CORP.

1. Record all preset and theft codes from the radio.

2. Turn off all lamps and accessories.

3. Turn the ignition switch to the LOCK position.

4. Open the negative battery cable cover.

5. Loosen the negative battery cable nut.

result in personal injury and/or damage to the vehicle or its
components.

2007 Hummer H3

2007 ENGINE Engine Electrical - H3