Hummer H3. Manual — part 1654

Circuit Description

The Service 4WD indicator is located in the instrument panel cluster (IPC) and shares the
common power and ground of the IPC. The transfer case shift control module controls the
Service indicator by sending the IPC a Class 2 message. This indicator may be controlled with the
scan tool using the IPC device controls.

Test Description

The number below refers to the step number on the diagnostic table.

2: This step determines whether the failure is the result of a malfunctioning transfer case
shift control module or the IPC.

Service Indicator Always On

Step

Action

Yes

No

Schematic Reference: Transfer Case Control Schematics
Connector End View Reference: Transfer Case Control Connector End Views

1

Did you perform the Diagnostic System
Check - Vehicle?

Go to Step 2

Go to
Diagnostic
System Check
- Vehicle

2

Observe the Service 4WD parameter
input/output in the instrument panel cluster
(IPC) Scan Tool Data List.
Is the Service 4WD indicator commanded
ON?

Go to Step 3

Go to Step 4

3

Replace the transfer case shift control module.
Refer to Control Module References for
replacement, setup and programming.
Did you complete the repair?

Go to Step 5

-

4

Replace the IPC. Refer to Instrument
Cluster Replacement (Left Hand Drive) or
Instrument Cluster Replacement (Right
Hand Drive) .
Did you complete the repair?

Go to Step 5

-

5

1. Use the scan tool in order to clear the

DTCs.

2. Operate the vehicle in order to

2007 Hummer H3

2007 TRANSMISSION Transfer Case - BW 4493/4494 - H3

SERVICE INDICATOR INOPERATIVE

Circuit Description

The Service 4WD indicator is located in the instrument panel cluster (IPC) and shares the
common power and ground of the IPC. The transfer case shift control module controls the
Service indicator lamp by sending the IPC a Class 2 message. This lamp may be controlled with
the scan tool using the IPC device controls.

Test Description

The number below refers to the step number on the diagnostic table.

2: This step determines whether the failure is the result of a faulty transfer case shift control
module or the IPC.

Service Indicator Inoperative

determine if the symptom has been
corrected.

Is the symptom still present?

Go to Step 1

System OK

Step

Action

Yes

No

Schematic Reference: Transfer Case Control Schematics
Connector End View Reference: Transfer Case Control Connector End Views

1

Did you perform the Diagnostic System
Check - Vehicle?

Go to Step 2

Go to
Diagnostic
System Check
- Vehicle

2

Observe the Service 4WD parameter
input/output in the instrument panel cluster
(IPC) Scan Tool Data List.
Is the Service 4WD indicator commanded
ON?

Go to Step 4

Go to Step 3

3

Replace the transfer case shift control
module. Refer to Control Module
References for replacement, setup and
programming.
Did you complete the repair?

Go to Step 5

-

Replace the IPC. Refer to Instrument

2007 Hummer H3

2007 TRANSMISSION Transfer Case - BW 4493/4494 - H3

TRANSFER CASE POPPING NOISE

Transfer Case Popping Noise

TRANSFER CASE WHINE OR RUMBLE NOISE

Transfer Case Whine or Rumble Noise

4

Cluster Replacement (Left Hand Drive) or
Instrument Cluster Replacement (Right
Hand Drive) .
Did you complete the repair?

Go to Step 5

-

5

1. Use the scan tool in order to clear the

DTCs.

2. Operate the vehicle in order to

determine if the symptom has been
corrected.

Is the symptom still present?

Go to Step 1

System OK

Cause

Correction

DEFINITION: A faulty internal transfer case component that causes a popping noise in the
transfer case.
Review the Symptoms - Transfer Case and perform the necessary inspections.
Chain jump

Replace the chain and sprockets. Refer to Transfer Case
Disassemble and Transfer Case Assemble.

Replace the shaft bearings. Refer to Transfer Case
Disassemble andTransfer Case Assemble.

Inspect for damaged components caused by metal debris.
Refer to Transfer Case Disassemble and Transfer
Case Assemble.

Cause

Correction

DEFINITION: A faulty internal transfer case component that causes a whine noise in the
transfer case.
Review the Symptoms - Transfer Case and perform the necessary inspections.
Faulty bearings

1. Inspect all of the bearings and journals. Refer to

Cleaning and Inspection.

2. Replace any faulty bearings and any components with

2007 Hummer H3

2007 TRANSMISSION Transfer Case - BW 4493/4494 - H3

TRANSFER CASE GROWL OR GRINDING NOISE

Transfer Case Growl or Grinding Noise

faulty bearing journals. Refer to Transfer Case
Disassemble and Transfer Case Assemble.

Cause

Correction

DEFINITION: A faulty internal transfer case component that causes a growl or grinding
noise in the transfer case while the vehicle is turning.
Review the Symptoms - Transfer Case and perform the necessary inspections.
High/low planetary carrier
assembly

1. Inspect the high/low planetary carrier pinion gears for

the following conditions:

Chipped, bent or deformed teeth

Pinion gear needle bearing worn

Pinion gear thrust washers missing

Seized or binding pinion gears

Refer to Cleaning and Inspection.

2. Inspect the high/low planetary carrier input gear for

excessive thrust end play.

3. Inspect the input gear teeth for excessive wear or

damage.

4. Replace the high/low planetary carrier assembly if any of

the above conditions exist. Refer to Transfer Case
Disassemble and Transfer Case Assemble.

Ring gear

1. Inspect the ring gear for teeth damage or wear. Refer to

Cleaning and Inspection.

2. Replace the ring gear if it is faulty. Refer to Transfer

Case Disassemble and Transfer Case Assemble.

Planetary differential

1. Inspect the planetary differential pinion gears for the

following conditions:

Chipped, bent or deformed teeth

Pinion gear bushings worn

Pinion gear thrust washers missing

Seized or binding pinion gears

2007 Hummer H3

2007 TRANSMISSION Transfer Case - BW 4493/4494 - H3