Hummer H2. Manual - part 274

Callouts For Fig. 12 

Radio Poor Reception 

Refer to the table when testing the antenna and/or lead-in cable. 

1. Measure the resistance from the coax center conductor to antenna mast.  

2. Total resistance from end to end of center conductor: 

z

RG-58/RG-59 type cable - less than 0.20 ohm  

z

RG-62/RG-62M type cable - less than 3.5 ohm  

3. When checking the resistance, cautiously wiggle the lead-in tip and cable. Refer to Testing for 

Intermittent Conditions and Poor Connections in Wiring Systems.  

4. Measure the resistance from the cable center conductor to metal case.  

5. Replace the antenna and/or lead-in cable when the above readings are not obtained.  

Some vehicles come equipped with a pre-amplified AM/FM antenna that is powered by SW 12+. If the antenna 
loses this power source or a ground, poor reception can occur. To see if your vehicle is equipped with a pre-
amplified antenna refer to Radio/Audio System Schematics (non Class 2 Amplifier) or Radio/Audio System 

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

1 and 6

Less than 0.2

1 and 2

Infinite

1 and 5

Infinite

1 and 7

Infinite

2 and 3

Infinite

2 and 4

Infinite

2 and 6

Infinite

3 and 4

Less than 0.2

3 and 6

Less than 0.2

3 and 5

Infinite

3 and 7

Infinite

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Entertainment - Hummer H2

  

Schematics (Class 2 Amplifier) . 

AUDIO DISTORTION - ONE OR MORE SPEAKERS 

Audio Distortion - One or More Speakers 

RADIO DISPLAYS LOC, LOCKED, OR CODE 

Radio Displays LOC, LOCKED, or CODE 

Step

Action

Yes

No

Schematic Reference: Radio/Audio System Schematics (non Class 2 Amplifier) or Radio/Audio 
System Schematics (Class 2 Amplifier) 
Connector End View Reference: Entertainment Connector End Views 
DEFINITION: This table is used for vehicles equipped with an audio amplifier.

1

Did you perform the Radio/Audio System Diagnostic System 
Check?

Go to 

Step 2

Go to Diagnostic System 

Check - Entertainment 

System

2

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

2. Turn ON the radio.  

3. Adjust the fade and balance controls to mid range.  

4. Insert the tape or CD from the J 39916-A CD and 

Cassette Diagnostic Audio Kit. See Special Tools and 
Equipment .  

Can audio distortion be heard from any speaker?

Go to 

Step 3

Go to Testing for 

Intermittent Conditions 

and Poor Connections

3

Test the appropriate speaker output circuits between the radio 
and the audio amplifier for an open, a short to ground, or 
short to voltage. Refer to Circuit Testing and Wiring 
Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to 

Step 6

Go to Step 4

4

Inspect for poor connections at the harness connector of the 
radio. 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 6

Go to Step 5

5

Replace the radio. Refer to Radio Replacement in 
Entertainment. 
Did you complete the replacement?

Go to 

Step 6

-

6

Operate the system in order to verify the repair. 
Did you correct the condition?

System 

OK

-

Step

Action

Yes

No

Schematic Reference: Radio/Audio System Schematics (non Class 2 Amplifier) or Radio/Audio 
System Schematics (Class 2 Amplifier)

Did you perform the Diagnostic System 

Go to Diagnostic System 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Entertainment - Hummer H2

  

RADIO DISPLAYS CLN OR CLEAN 

Radio Displays CLN or CLEAN 

1

Check - Entertainment System?

Go to Step 2

Check - Entertainment 

System

2

1. Turn ON the ignition, with the 

engine OFF.  

2. Turn ON the radio.  

Does the radio operate normally?

Go to Testing for 

Intermittent Conditions and 

Poor Connections in Wiring 

Systems

Go to Step 3

3

1. Reprogram the radio. Refer to 

Service Programming System 
(SPS) in Vehicle Control Systems. 

2. Turn OFF the ignition.  

3. Turn ON the ignition, with the 

engine OFF.  

4. Turn ON the radio.  

Does the radio display Locked?

Go to Step 4

Go to Step 5

4

Replace the radio. Refer to Radio 
Replacement .Did you complete the 
replacement?

IMPORTANT:

Reprogram the radio. Refer to Service 
Programming System (SPS) in Vehicle 
Control Systems.

Go to Step 5

-

5

Operate the system in order to verify the 
repair. 
Did you correct the condition?

System OK

Go to Step 2

Step

Action

Yes

No

Schematic Reference: Radio/Audio System Schematics (non Class 2 Amplifier) or Radio/Audio 
System Schematics (Class 2 Amplifier)

1

Did you perform the Diagnostic System 
Check - Entertainment System?

Go to Step 2

Go to Diagnostic 

System Check - 

Entertainment System

2

1. Turn ON the ignition, with the 

engine OFF.  

2. Turn ON the radio.  

Does the radio operate normally?

Go to Testing for 

Intermittent Conditions 

and Poor Connections in 

Wiring Systems

Go to Step 3

1. Clean the tape head path usingJ 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Entertainment - Hummer H2

  

RADIO DISPLAYS CAL OR CAL ERR 

Radio Displays CAL or CAL ERR 

3

39916-A CD and Cassette 
Diagnostic Audio Kit. See Special 
Tools and Equipment .  

2. Reset the display by pushing and 

holding the eject button for 5 
seconds.  

Does the radio display CLN or CLEAN?

Go to Step 4

Go to Step 5

4

Replace the radio. Refer to Radio 
Replacement .Did you complete the 
replacement?

IMPORTANT:

Reprogram the radio. Refer to Service 
Programming System (SPS) in Vehicle 
Control Systems.

Go to Step 5

-

5

Operate the system in order to verify the 
repair. 
Did you correct the condition?

System OK

Go to Step 3

Step

Action

Yes

No

Schematic Reference: Radio/Audio System Schematics (non Class 2 Amplifier) or Radio/Audio 
System Schematics (Class 2 Amplifier)

1

Did you perform the Diagnostic System 
Check - Entertainment System?

Go to Step 2

Go to Diagnostic System 

Check - Entertainment 

System

2

1. Turn ON the ignition, with the 

engine OFF.  

2. Turn ON the radio.  

Does the radio operate normally?

Go to Testing for 

Intermittent Conditions and 

Poor Connections in Wiring 

Systems

Go to Step 3

3

1. Reprogram the radio. Refer to 

Service Programming System 
(SPS) in Vehicle Control Systems. 

2. Turn OFF the ignition.  

3. Turn ON the ignition, with the 

engine OFF.  

4. Turn ON the radio.  

Does the radio display CAL ERR?

Go to Step 4

Go to Step 5

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Entertainment - Hummer H2