Hummer H2. Manual - part 318

COURTESY LAMPS INOPERATIVE 

Courtesy Lamps Inoperative 

12

Replace the body control module (BCM). Refer to 
Body Control Module Replacement in Body Control 
System.Did you complete the replacement?

Go to Step 13

-

13

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: Interior Lights SchematicsBody Control System Schematics 
Connector End View Reference: Lighting Systems Connector End Views , Body Control System 
Connector End Views or Master Electrical Component List

1

Did you perform the Lighting Systems Diagnostic System 
Check?

Go to Step 2

Go to 

Diagnostic 

System Check -

Lighting 

Systems

2

Verify that the courtesy/dome lamps are inoperative. 
Do the courtesy/dome lamps operate normally?

Go to Testing for 

Intermittent 

Conditions and Poor 

Connections in 

Wiring Systems

Go to Step 3

3

Are all courtesy lamps inoperative?

Go to Step 5

Go to Step 4

4

Test the voltage supply and ground circuits of the 
inoperative lamp for an open or high resistance. Refer to 
Circuit Testing andWiring Repairs In Wiring Systems. 
Did you find and correct the condition?

Go to Step 16

Go to Step 14

5

Are the courtesy lamps inoperative from a specific switch 
only?

Go to Step 6

Go to Step 11

6

Inspect the following related body control module (BCM), 
driver door module (DDM), passenger door module 
(PDM) data parameters, and check for a ground signal on 
the lift gate ajar signal circuit of the BCM with the lift gate 
open. Refer to Scan Tool Data List and Scan Tool Data 
Definitions for typical values and definitions: 

z

The courtesy lamp switch  

z

The interior lamp defeat switch  

z

The door ajar switches  

 
Was a problem found?

Go to Step 7

Go to Step 10

Disconnect and test the switch of the affected input circuit 
for proper continuity in the open and closed positions. 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

7

Refer to Testing for Continuity in Wiring Systems. 
Is continuity correct in both positions?

Go to Step 8

Go to Step 9

8

Test the signal and ground circuits of the affected input 
circuit for a short to ground, open or high resistance. Refer 
to Circuit Testing and Wiring Repairs in Wiring 
Systems. 
Did you find and correct the condition?

Go to Step 16

Go to Step 10

9

Inspect for poor connections at the harness connector of 
the affected switch. 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 16

Go to Step 12

10

Inspect for poor connections at the harness connector of 
the module in the affected circuit. 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 16

Go to Step 13

11

Inspect for poor connections at the harness connector of 
the BCM. 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 16

Go to Step 15

12

Replace the switch in the affected circuit. 
Did you complete the replacement?

Go to Step 16

-

13

Replace the module in the affected circuit. Refer to the 
appropriate replacement procedure: 

z

Body Control Module Replacement in Body 
Control Systems  

z

Switch Replacement - Door Lock and Side 
Window - Driver in Doors  

z

Switch Replacement - Door Lock and Side 
Window - Passenger in Doors  

Did you complete the replacement?

IMPORTANT:

Perform the setup procedure for the replacement 
module as applicable.

Go to Step 16

-

14

Replace the inoperative bulb. 
Did you complete the repair?

Go to Step 16

-

15

Replace the body control module (BCM). Refer to Body 

IMPORTANT:

Perform the setup procedure for the BCM.

-

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

DAYTIME RUNNING LAMPS (DRL) ALWAYS ON 

Daytime Running Lamps (DRL) Always On 

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

Go to Step 16

16

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 Diagnostic System 
Check?

Go to Step 2

Go to Diagnostic 

System Check - 

Lighting Systems

2

1. Ensure the park brake is released.  

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

3. With the brake pedal depressed, place the gear 

selector in any drive gear.  

4. Place the headlamps in the ON position.  

Does the system operate normally?

Go to Testing for 

Electrical 

Intermittents in 

Wiring Systems

Go to Step 3

3

1. Place the headlamps in the AUTO position.  

2. Disconnect the daytime running lamp (DRL) 

relay.  

Do the DRL turn OFF?

Go to Step 4

Go to Step 7

4

1. Reconnect the DRL relay.  

2. Use the scan tool to observe the DRL parameter 

and command the DRL ON and OFF several 
times.  

Does the DRL parameter change states as expected?

Go to Step 5

Go to Step 6

5

Inspect for poor connections at the harness connector 
of the DRL relay. Refer to Testing for Intermittent 
Conditions and Poor Connections andConnector 
Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 10

Go to Step 8

6

Inspect for poor connections at the harness connector 
of the body control module (BCM). 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 10

Go to Step 9

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

DAYTIME RUNNING LAMPS (DRL) INOPERATIVE 

Daytime Running Lamps (DRL) Inoperative 

7

Repair the DRL supply voltage circuit. Refer to 
Wiring Repairs in Wiring Systems. 
Did you complete the repair?

Go to Step 10

-

8

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

Go to Step 10

-

9

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 10

-

10

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 
Component 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 Diagnostic System 
Check?

Go to Step 2

Go to Diagnostic 

System Check - 

Lighting Systems

2

1. Block the drive wheels.  

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

3. Place the gear selector in the DRIVE position.  

4. Ensure the headlamp switch is in the AUTO 

position.  

5. Ensure the ambient light sensor is not covered 

or has no obstruction to daylight.  

Does the system operate normally?

Go to Testing for 

Electrical 

Intermittents in 

Wiring Systems

Go to Step 3

3

Is only one DRL inoperative?

Go to Step 4

Go to Step 5

4

Test the supply and ground circuits of the affected 
lamp for a high resistance or an open. Refer to 
Circuit Testing andWiring Repairs in Wiring 
Systems. 
Did you find and correct the condition?

Go to Step 16

Go to Step 15

1. Ensure the park brake is not set.  

2. Install a scan tool.  

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2