Hummer H3. Manual — part 1199

3

1. Turn the ignition ON with the engine

OFF.

2. With a scan tool, observe the Talk

Button Switch data parameter in the
body control module (BCM) data list.

3. Depress the Talk Button Switch

Does the scan tool display change from
Inactive to Active?

Go to Step 8

Go to Step 4

4

1. Disconnect the headlamp and panel

dimmer switch. Refer to Headlamp
Switch Replacement .

2. Place a fused jumper between the

headlamp switch headlamps on signal
circuit and low reference circuit
terminals.

Does the scan tool change from Inactive to
Active?

Go to Step 6

Go to Step 5

5

Test for one of the following conditions in
the headlamp and panel dimmer switch
circuits. Refer to Circuit Testing and
Wiring Repairs .

An open or short to ground in the
Voice Recognition Switch Signal
circuit.

A open or short to ground in the low
reference circuit.

Go to Step 9

Go to Step 7

6

Inspect for poor connections at the harness
connector of the headlamp and panel
dimmer switch. Refer to Circuit Testing
and Wiring Repairs .
Did you find and correct the condition?

Go to Step 9

Go to Step 7

7

Replace the headlamp and panel dimmer
switch. Refer to Headlamp Switch
Replacement .
Did you complete the repair?

Go to Step 9

-

2007 Hummer H3

2007 ACCESSORIES AND EQUIPMENT Cellular, Entertainment and Navigation - H3

RADIO POOR RECEPTION

Reference Information

Schematic Reference:

Radio/Navigation System Schematics

Connector End View Reference:

Entertainment/Communication Connector End Views

Diagnostic System Check - Entertainment System

Always perform the Diagnostic System Check before proceeding with these diagnostic
procedures. Refer to Diagnostic System Check - Vehicle .

Antenna System Test

1. Disconnect the negative battery cable.

2. Disconnect the antenna lead-in connector from the radio receiver.

3. Measure the resistance from the negative battery cable to the coax outer conductor

connector.

4. The resistance measured should be 0.2 ohms or less.

5. Test the following when the resistance is greater than 0.2 ohms.

Base of the antenna for a poor connection to body ground

8

Replace the BCM. Refer to Control
Module References for replacement,
setup and programming.
Did you complete the replacement?

Go to Step 9

-

9

1. Use the scan tool in order to clear any

induced DTCs.

2. Operate the system in order to verify

the repair.

Did you correct the condition?

System OK

Go to Step 2

IMPORTANT: Always zero out the DMM before taking a resistance

measurement in order to ensure an accurate reading.

2007 Hummer H3

2007 ACCESSORIES AND EQUIPMENT Cellular, Entertainment and Navigation - H3

The coaxial cable interconnects for a poor connection or corrosion.

Test for an open or high resistance from the battery negative cable to the body. Refer
to Circuit Testing and Wiring Repairs .

6. After finding and correcting the condition, operate the system in order to verify the repair.

Perform the Antenna Checking Procedures after confirming the integrity of the antenna ground.

Antenna Checking Procedures

Perform the following tests for the type of antenna on the vehicle.

Mast Antennas

Unplug the antenna lead-in connector from the radio receiver and plug a test antenna into the
radio. Ensure the antenna base is grounded to the vehicle chassis and keep your hands off the
mast.

Check the radio reception in an area away from electrical interferences. Tune to several weak and
strong AM and FM stations. If the radio reception improved, the problem exists with the antenna
and/or lead-in cable. If the reception is still poor, refer to Audio System Troubleshooting
Hints.

IMPORTANT: Always zero out the DMM before taking a resistance

measurement in order to ensure an accurate reading.

2007 Hummer H3

2007 ACCESSORIES AND EQUIPMENT Cellular, Entertainment and Navigation - H3

Fig. 32: Identifying Mast Antenna System Components
Courtesy of GENERAL MOTORS CORP.

Callouts For Fig. 32

Radio Poor Reception

Callout

Component Name

1

Negative Battery Cable

2

Coaxial Cable Conductor - Radio End

3

Coaxial Cable Metal Outer Shield - Radio End

4

Coaxial Cable Metal Outer Shield - Antenna End

5

Coaxial Cable Conductor - Antenna End

6

Antenna Base

7

Antenna Mast

8

Antenna Coaxial Cable

Ohmmeter Probes At Points

Resistance Measured In Ohms

1 and 3

Less than 0.2

1 and 4

Less than 0.2

2007 Hummer H3

2007 ACCESSORIES AND EQUIPMENT Cellular, Entertainment and Navigation - H3