Hummer H3. Manual - part 13

Conditions and Poor Connections and
Connector Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 28

Go to Step 26

Inspect for poor connections at the harness
connector of the PCM. 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 28

Go to Step 27

Repair an open or high resistance in the battery
positive voltage circuit of the STARTER relay
coil. Refer to Wiring Repairs in Wiring
Systems.
Did you complete the repair?

Go to Step 28

Repair the open or high resistance in the battery
positive voltage circuit of the STARTER relay
switch. Refer to Wiring Repairs in Wiring
Systems.
Did you complete the repair?

Go to Step 28

Repair the short to ground in the starter
solenoid crank voltage circuit. Refer to Wiring
Repairs in Wiring Systems.
Did you complete the repair?

Go to Step 28

Replace the STARTER relay. Refer to Relay
Replacement (Within an Electrical Center)
or Relay Replacement (Attached to Wire
Harness) in Wiring Systems.
Did you complete the replacement?

Go to Step 28

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

Go to Step 28

Replace the ignition switch. Refer to
IGNITION LOCK CYLINDER
REPLACEMENT in Steering Wheel and
Column.
Did you complete the replacement?

Go to Step 28

Replace the PCM. Refer to Control Module
References in Computer/Integrating Systems

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

STARTER SOLENOID CLICKS, ENGINE DOES NOT CRANK

Starter Solenoid Clicks, Engine Does Not Crank

for replacement, setup, and programming.
Did you compete the replacement?

Go to Step 28

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

System OK

Go to Step 2

Step

Action

Yes

Schematic Reference: Starting and Charging Schematics

Did you perform the Diagnostic System Check -
Vehicle?

Go to Step 2

Go to Diagnostic
System Check -
Vehicle

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

Go to Step 3

Go to Starter
Solenoid Does
Not Click

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

Go to Step 4

Go to Engine
Will Not Crank
- Crankshaft
Will Not Rotate
for the 3.5L
engine

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

Go to Step 8

Go to Step 5

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

Go to Step 8

Go to Step 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

Replace the starter. Refer to Starter Motor
Replacement.

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

ENGINE CRANKS SLOWLY

Perform the following checks:

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

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.

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 in this section.

STARTER MOTOR NOISE DIAGNOSIS

Diagnostic Aids

Inspect the flywheel ring gear for damage or unusual wear.

Starter Motor Noise Diagnosis

Did you complete the replacement?

Go to Step 8

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

System OK

Go to Step 2

Step

Action

Yes

Did you perform the Diagnostic System Check
- Vehicle?

Go to Step 2

Go to Diagnostic
System Check -
Vehicle

Start the engine.
Does the starter operate normally?

Go to Testing
for Intermittent
Conditions and
Poor
Connections

Go to Step 3

Start the engine while listening to the starter
motor turn.
Is there a loud "whoop", it may sound like a

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

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

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

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

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

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 9

Go to Step 8

Replace the flywheel. Refer to Engine
Flywheel Replacement (w/Automatic
Transmission) or Engine Flywheel
Replacement (w/Manual Transmission) for
the 3.5L engine.
Did you complete the replacement?

Go to Step 10

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

Go to Step 10

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

System OK

Go to Step 3

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

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