Hummer H2. Manual - part 320

 

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Hummer H2. Manual - part 320

 

 

5

z

The headlamp dimmer switch signal  

z

The headlamp switch flash to pass (FTP) 
signal  

 
Did you find and correct a condition?

Go to Step 18

Go to Step 6

6

Remove the high beam relay. 
Do the high beam headlamps remain ON?

Go to Step 12

Go to Step 7

7

Test for a ground signal at the high beam relay 
control circuit connector terminal. Refer to 
Circuit Testing in Wiring Systems. 
Is a ground control signal present?

Go to Step 11

Go to Step 15

8

Remove the low beam relay. 
Do the low beam headlamps remain always ON?

Go to Step 13

Go to Step 9

9

Test for a ground signal at the headlamp low 
beam relay control circuit connector terminal of 
the relay. Refer to Circuit Testing in Wiring 
Systems. 
Is a ground signal present?

Go to Step 11

Go to Step 16

10

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

Go to Step 18

Go to Step 17

11

Inspect for poor connections at the harness 
connector of the body control module (BCM). 
Refer to Circuit Testing and Wiring Repairs in 
Wiring Systems. 
Did you find and correct the condition?

Go to Step 18

Go to Step 14

12

Repair the short to voltage in the right or left 
high beam headlamp supply voltage circuit. 
Refer to Wiring Repairs in Wiring Systems. 
Did you find and correct a condition?

Go to Step 18

-

13

Repair the short to voltage in the right or left 
low beam headlamp supply voltage circuit. 
Refer to Wiring Repairs in Wiring Systems. 
Did you find and correct a condition?

Go to Step 18

-

14

Replace the BCM. Refer to Body Control 
Module Replacement in Body Control 
System.Did you complete the replacement?

IMPORTANT:

Perform the setup procedure for the BCM.

Go to Step 18

-

Replace the high beam headlamp relay. Refer to 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

HEADLAMPS INOPERATIVE - HIGH BEAMS 

Headlamps Inoperative - High Beams 

15

Relay Replacement (Within an Electrical 
Center)Relay Replacement (Attached to Wire 
Harness) in Wiring Systems. 
Did you complete the repair?

Go to Step 18

-

16

Replace the low beam relay. Refer to Relay 
Replacement (Within an Electrical Center)
Relay Replacement (Attached to Wire 
Harness) in Wiring Systems. 
Did you complete the repair?

Go to Step 18

-

17

Replace the headlamp dimmer switch. Refer to 
Multifunction, Turn Signal Switch 
Replacement in Steering Wheel and Column. 
Did you complete the repair?

Go to Step 18

-

18

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:Headlights/Daytime Running Lights (DRL) Schematics 
Connector End View Reference:Lighting Systems Connector End Views or Body Control System 
Connector End Views in Body Control System

1

Did you perform the Lighting Systems 
Diagnostic System Check?

Go to Step 2

Go to Diagnostic 

System Check - 

Lighting Systems

2

1. Place the headlamp switch in the ON 

position.  

2. Place the dimmer switch in the high beam 

position.  

Do the high beam headlamps operate normally?

Go to Testing for 

Intermittent Conditions 

and Poor Connections in 

Wiring Systems

Go to Step 3

3

Is only one high beam headlamp inoperative?

Go to Step 4

Go to Step 5

4

Test the high beam headlamp supply voltage 
circuit for high resistance, an open or a short to 
ground. Refer to Circuit Testing and Wiring 
Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 15

Go to Step 8

5

1. Disconnect the headlamp high relay.  

2. Connect a test lamp between the control 

circuit of the headlamp high relay and the 
battery positive voltage circuit of the 
headlamp high relay connector.  

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

Does the test lamp illuminate?

Go to Step 13

Go to Step 6

6

1. Connect the headlamp high relay.  

2. Test the headlamp dimmer switch signal 

and ground circuits for an open or high 
resistance. Refer to Circuit Testing and 
Wiring Repairs in Wiring Systems.  

Did you find and correct a condition?

Go to Step 15

Go to Step 7

7

1. Place the headlamp switch in the ON 

position.  

2. Connect a fused jumper from ground to the 

headlamp dimmer switch signal terminal 
of the headlamp dimmer switch connector. 

Do the high beam headlamps illuminate?

Go to Step 9

Go to Step 10

8

Inspect for poor connections at the harness 
connector of the inoperative bulb. Refer to 
Circuit Testing and Wiring Repairs in Wiring 
Systems. 
Did you find and correct the condition?

Go to Step 15

Go to Step 11

9

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

Go to Step 15

Go to Step 14

10

Inspect for poor connections at the harness 
connector of the Body Control Module (BCM). 
Refer to Circuit Testing and Wiring Repairs in 
Wiring Systems. 
Did you find and correct the condition?

Go to Step 15

Go to Step 12

11

Replace the high beam bulb. Refer to Headlamp 
Replacement or Headlamp Bulb 
Replacement . 
Did you complete the replacement?

Go to Step 15

-

12 Replace the body control module (BCM). Refer 

to Body Control Module Replacement in Body 
Control System.Did you complete the 
replacement?

IMPORTANT:

Perform the setup procedure for the BCM.

Go to Step 15

-

13

Replace the high beam headlamp relay. Refer to 
Relay Replacement (Within an Electrical 
Center)Relay Replacement (Attached to Wire 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

HEADLAMPS INOPERATIVE - LOW BEAMS 

Headlamps Inoperative - Low Beams 

Harness) in Wiring Systems. 
Did you complete the replacement?

Go to Step 15

-

14

Replace the headlamp dimmer switch. Refer to 
Multifunction, Turn Signal Switch 
Replacement in Steering Wheel and Column. 
Did you complete the repair?

Go to Step 15

-

15

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: Headlights/Daytime Running Lights (DRL) Schematics 
Connector End View Reference: Lighting Systems Connector End Views or Body Control System 
Connector End Views in Body Control System.

1

Did you perform the Lighting Systems Diagnostic 
System Check?

Go to Step 2

Go to Diagnostic 

System Check - 

Lighting Systems

2

1. Place the headlamp switch in the ON 

position.  

2. Place the dimmer switch in the low beam 

position.  

Do the low beam headlamps operate normally?

Go to Testing for 

Intermittent Conditions 

and Poor Connections in 

Wiring Systems

Go to Step 3

3

Is only one low beam headlamp inoperative?

Go to Step 4

Go to Step 5

4

Test the headlamp low beam supply voltage and 
ground circuits for high resistance, an open or a 
short to ground. Refer to Circuit Testing and 
Wiring Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 16

Go to Step 9

5

1. Disconnect the headlamp low relay.  

2. Connect a test lamp between the control 

circuit of the headlamp low relay and the 
battery positive voltage circuit of the 
headlamp low relay connector.  

Does the test lamp illuminate?

Go to Step 14

Go to Step 6

6

1. Connect the headlamp low relay.  

2. Place the headlamp switch in the HEAD 

position.  

3. Disconnect the multifunction switch.  

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

 

 

 

 

 

 

 

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