Hummer H3. Manual — part 1192

Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of the system. Refer to
Checking Aftermarket Accessories .

Inspect the easily accessible or visible system components for obvious damage or conditions
which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to
Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the
symptom:

OnStar One or More Buttons Inoperative

OnStar Call Center Remote Function Requests Inoperative

Unable to Contact OnStar Call Center

OnStar Microphone Inoperative - Caller Cannot Be Heard

OnStar Voice Recognition Inoperative

OnStar Button LED Inoperative

No (or Noisy) OnStar Audio

OnStar Global Positioning System (GPS) Data Not Current or Inaccurate

OnStar Talk Button Inoperative

SYMPTOMS - ENTERTAINMENT

Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of the Radio/Audio system.
Refer to Checking Aftermarket Accessories .

Inspect the easily accessible or visible system components for obvious damage or conditions
which could cause the symptom.

IMPORTANT: Review the system operation in order to familiarize yourself with

the system functions. Refer to Radio/Audio System Description
and Operation.

2007 Hummer H3

2007 ACCESSORIES AND EQUIPMENT Cellular, Entertainment and Navigation - H3

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to
Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the
symptom:

Radio Poor Reception

Digital Radio Poor or No Reception

Reduced Volume - One or More Speakers (W UM8) or Reduced Volume - One or
More Speakers (w/o UM8)

Speakers Inoperative - One or More

SYMPTOMS - NAVIGATION SYSTEMS

Perform the Diagnostic System Check - Vehicle before using the symptom tables in order
to verify that all of the following are true:

There are no DTCs set.

The control modules can communicate via the serial data link.

Review Navigation System Description and Operation in order to familiarize yourself
with the system functions.

Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of the navigation system
components. Refer to Checking Aftermarket Accessories .

Inspect the easily accessible or visible system components for obvious damage or conditions
which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to
Testing for Intermittent Conditions and Poor Connections .

IMPORTANT: The following steps must be completed before using the symptom

tables.

2007 Hummer H3

2007 ACCESSORIES AND EQUIPMENT Cellular, Entertainment and Navigation - H3

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the
symptom:

No Global Positioning System (GPS) Reception

For radio/audio related symptoms, refer to Symptoms - Entertainment.

AUDIO SYSTEM TROUBLESHOOTING HINTS

Many conditions that affect radio operation may be corrected without removing the radio from
the car. Verify the condition and follow the diagnostic procedures in order to isolate and correct
the condition. In order to properly diagnose any audio system problems, ensure that you have a
fully charged battery.

Preliminary Inspections

Check for any aftermarket equipment that may have been installed on the vehicle. If
aftermarket equipment is found disconnect it and check if the audio noise is still present.

Inspect that the antenna connector and the antenna coaxial cable are clean and tight.

For reception concerns, first determine if the customer is within the listening area of the
stations they are attempting to receive.

Stations at the lower end of the FM band are more susceptible to audio noises than stations
at the higher end.

If the noise is only from one speaker check for the following before speaker replacement:

Isolate the noise using the J 39916-A CD and Cassette Diagnostic Audio Kit.

Inspect the speaker connections to ensure they are clean and tight. Refer to Testing
for Intermittent Conditions and Poor Connections .

Inspect for a loose or incorrectly installed speaker or surrounding trim. Loose trim can
cause a buzz or flutter which sounds like a malfunctioning speaker.

Ignition noise on the FM band may be an indication of an ignition system problem.

Inspect that all vehicle grounds are clean, tight and free of corrosion.

Inspect the rear defogger grid lines for large breaks or dark spots.

IMPORTANT: When testing the audio system for poor reception or noise,

the vehicle should be outside away from metal buildings and
utility lines, with the hood and rear compartment closed.

2007 Hummer H3

2007 ACCESSORIES AND EQUIPMENT Cellular, Entertainment and Navigation - H3

Inspect the connections at the radio antenna module if equipped, to ensure that they are
clean and tight.

Compare the customers vehicle to another of similar model and audio system to determine if
the condition is abnormal.

Identifying Concerns

1. In order to isolate the source of the noise/poor reception, identify the ignition switch

position that the concern is most noticeable:

1. Turn the ignition switch to the accessory position.

2. Turn ON the radio.

3. Seek up 88-108 FM then 550-1600 AM.

4. Record the number of valid radio stations where the tuner stops.

5. Repeat these steps with the ignition ON and the engine OFF then again with the engine

running.

2. Return the ignition switch to the position that the concern was most noticeable.

3. Remove fuses or circuit breakers one at a time until the noise has been eliminated.

4. Identify what systems or components are powered by the fuse.

5. Reinstall all fuses and circuit breakers.

6. Disconnect the components powered by the fuse one at a time until the concern has been

eliminated.

Corrective Action

Inspect the ground integrity of the component or system causing the noise.

Malfunctioning and marginal components such as relays and solenoids may cause noise
and/or poor reception.

Always use a braided ground strap when applying additional grounds and keep the ground
strap as short as possible.

If the noise source is found to be coming from the vehicle harness:

Route the antenna cable separately from the wire harness that is emitting the noise.

Use aluminum or nickel tape in order to shield the antenna cable. Try variations of the
following repairs:

Try adding only aluminum or nickel tape before adding a ground strap to the
tape.

Wrap a ground strap 360 degrees around the tape, securing the other end of the

2007 Hummer H3

2007 ACCESSORIES AND EQUIPMENT Cellular, Entertainment and Navigation - H3