Hummer H2. Manual — part 319

5

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

4. With the scan tool, observe the park brake

switch parameter in the Body Control Module
(BCM) data list.

Does the scan tool display RELEASED?

Go to Step 7

Go to Step 6

6

Test the signal circuit of the park brake switch for 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 10

7

1. Turn OFF the ignition.

2. Remove the daytime running lamps (DRL)

relay.

3. Connect a 3-amp fused jumper wire between

battery positive voltage and the DRL supply
voltage circuit of the DRL relay.

Do the DRL illuminate?

Go to Step 8

Go to Step 11

8

Test the DRL relay control circuit of the DRL relay
for a ground signal. Refer to Circuit Testing in
Wiring Systems.
Is a ground signal present?

Go to Step 14

Go to Step 9

9

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 12

10

Inspect for poor connections at the harness connector
of the park brake 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 13

11

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

Go to Step 16

-

12

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 16

-

13

Replace the park brake switch. Refer to Park Brake
Warning Lamp Switch Replacement in Park Brake.
Did you complete the replacement?

Go to Step 16

-

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

HAZARD LAMPS ALWAYS ON

Hazard Lamps Always On

14

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 16

-

15

Replace the inoperative DRL. Refer to Daytime
Running Lamp Replacement .
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:Exterior Lights 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

Turn OFF the hazard flashers.
Does the system operate normally?

Go to Testing for

Electrical

Intermittents in

Wiring Systems

Go to Step 3

3

1. Turn OFF the ignition.

2. Disconnect the turn signal/hazard flasher

module.

3. Connect a test lamp between the hazard flasher

signal circuit of the turn signal/hazard flasher
module connector and battery positive voltage.

Does the test lamp illuminate?

Go to Step 4

Go to Step 6

4

Test the hazard switch signal circuit of the turn
signal/hazard flasher module for a short to ground.
Refer to Circuit Testing and Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

Go to Step 9

Go to Step 5

5

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

Go to Step 9

Go to Step 7

6

Inspect for poor connections at the harness connector
of the turn signal/hazard flasher module. Refer to
Testing for Intermittent Conditions and Poor

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

HAZARD LAMPS INOPERATIVE

Hazard Lamps Inoperative

Connections and Connector Repairs in Wiring
Systems.
Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

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

Go to Step 9

-

8

Replace the turn signal/hazard flasher module.
Did you complete the replacement?

Go to Step 9

-

9

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:Exterior Lights 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

Turn ON the hazard flashers.
Does the system operate normally?

Go to Testing for

Electrical

Intermittents in

Wiring Systems

Go to Step 3

3

1. Turn ON the ignition with the engine OFF.

2. Turn ON each turn signal.

Do the turn signals function properly?

Go to Step 4

Go to Turn Signal

Lamps and/or

Indicators

Inoperative

4

1. Turn OFF the ignition.

2. Disconnect the turn signal/hazard flasher

module.

3. Turn ON the hazard switch.

4. Connect a test lamp between the hazard flasher

signal circuit of the turn signal/hazard flasher
module connector and battery positive voltage.

Does the test lamp illuminate?

Go to Step 8

Go to Step 5

5

Test the hazard switch signal circuit of the turn
signal/hazard flasher module for high resistance or an
open. Refer to Circuit Testing and Wiring Repairs
in Wiring Systems.

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

HEADLAMPS ALWAYS ON - LOW OR HIGH BEAM

Headlamps Always On - Low or High Beam

Did you find and correct the condition?

Go to Step 11

Go to Step 6

6

Test the ground circuit of the multifunction switch for
high resistance or an open. Refer to Circuit Testing
and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 11

Go to Step 7

7

Inspect for poor connections at the harness connector
of the Multifunction 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 11

Go to Step 9

8

Inspect for poor connections at the harness connector
of the turn signal/hazard flasher module. 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 11

Go to Step 10

9

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

Go to Step 11

-

10

Replace the turn signal/hazard flasher module.
Did you complete the replacement?

Go to Step 11

-

11

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

Place the headlamp switch in the OFF position.
Do the high and low beam headlamps operate
normally?

Go to Testing for

Intermittent Conditions

and Poor Connections in

Wiring Systems

Go to Step 3

3

Are only the high beam headlamps always ON?

Go to Step 4

Go to Step 8

4

Disconnect the headlamp dimmer switch.
Do the high beam headlamps remain ON?

Go to Step 5

Go to Step 10

Test the following circuits for a short to ground
as applicable. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2