Hummer H2. Manual - part 1097

Did you find and correct the condition?

Go to Step 29

Go to Step 22

17

Inspect for poor connections at the starter motor relay. 
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 29

Go to Step 25

18

If equipped with an automatic transmission, inspect for 
poor connection at the PNP switch harness connector. 
Refer to Testing for Intermittent Conditions and Poor 
Connections and Connector Repairs in Wiring Systems. 
If OK, perform the Park/Neutral Position Switch 
Adjustment in Automatic Transmission - 4L60-E/4L65-E.
Did you find and correct the condition?

Go to Step 29

Go to Step 26

19

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 29

Go to Step 20

20

Replace the PCM/engine control module (ECM). Refer to 
Powertrain Control Module (PCM) Replacement in 
Engine Controls - 4.8L, 5.3L, and 6.0L.Is action complete?

IMPORTANT:

The replacement PCM must be programmed.

Go to Step 29

-

21

Inspect for poor connections at the ignition switch harness 
connector. 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 29

Go to Step 27

22

Inspect for poor connections at the starter solenoid. 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 29

Go to Step 28

23

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

Go to Step 29

-

24

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

Go to Step 29

-

25

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 29

-

Replace the PNP switch. Refer to Park/Neutral Position 

 

2004 Hummer H2 

2004 ELECTRICAL Engine Electrical - Hummer H2

  

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