Hummer H2. Manual — part 1167

9

1. Connect a test light from the supply voltage circuit

of the starter motor relay coil circuit to the control
circuit of the starter motor relay coil circuit.

2. With the transmission in park, turn the ignition

switch to the START position.

Does the test light illuminate?

Go to Step 17

Go to Step 14

10

1. Turn OFF the ignition.

2. Disconnect the park neutral position (PNP) switch.

Refer to Park/Neutral Position Switch
Replacement in Automatic Transmission - 4L60-
E/4L65-E.

3. Turn ON the ignition, with the engine OFF.

4. Connect a 10-amp fused jumper between the starter

motor relay coil control circuits of the PNP switch.

5. With the transmission in PARK, turn the ignition

switch to the START position.

Does the test lamp illuminate?

Go to Step 18

Go to Step 15

11

1. Turn OFF the ignition.

2. Disconnect the starter motor relay.

3. Connect a test lamp between the battery positive

voltage circuit of the starter motor relay switch
circuit and a good ground.

Does the test lamp illuminate?

Go to Step 12

Go to Step 23

12

Connect a 30-amp fused jumper between the battery
positive voltage circuit of the starter motor relay switch
circuit and the supply voltage circuit of the starter
solenoid.
Does the engine crank?

Go to Step 17

Go to Step 13

13 Does the fuse in the jumper open?

Go to Step 24

Go to Step 16

14

Test the control circuit of the starter motor relay for an
open or high resistance. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 29

Go to Step 25

15

Test the supply voltage circuit of the starter motor relay
coil circuit for an open or high resistance. Refer to Circuit
Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 29

Go to Step 21

16

Test the supply voltage circuit of the starter solenoid for an
open or high resistance. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

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