Hummer H3. Manual — part 1415

(Within an Electrical Center) .
Did the front fog lamps turn OFF?

Go to Step 5

Go to Step 8

5

Test for a voltage signal at the fog lamp
relay control circuit terminal for the front
fog lamp relay in the underhood fuse
block. Refer to Electrical Center
Identification Views and Circuit
Testing .
Was a voltage signal present?

Go to Step 7

Go to Step 10

6

Test for a short to ground in the front fog
lamp switch signal circuit. Refer to
Circuit Testing and Wiring Repairs .
Did you find and correct a condition?

Go to Step 12

Go to Step 11

7

Inspect for poor connections at the
harness connector of the BCM. Refer to
Circuit Testing and Wiring Repairs .
Did you find and correct a condition?

Go to Step 12

Go to Step 9

8

Repair the short to voltage in the front fog
lamp supply voltage circuit. Refer to
Wiring Repairs .
Did you complete the repair?

Go to Step 12

-

9

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

Go to Step 12

-

10

Replace the front fog lamp relay. Refer to
Relay Replacement (Attached to Wire
Harness) or Relay Replacement
(Within an Electrical Center) .
Did you complete the repair?

Go to Step 12

-

11

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

Go to Step 12

-

12

1. Use the scan tool in order to clear

any induced DTCs.

2. Operate the system in order to verify

the repair.

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Lighting - H3

FOG LAMPS INOPERATIVE

Fog Lamps Inoperative

Did you correct the condition?

System OK

Go to Step 3

Step

Action

Yes

No

Schematic Reference: Fog Lights Schematics
Connector End View Reference: Lighting Systems Connector End Views or Data
Communication Connector End Views

1

Did you perform the Diagnostic System
Check - Vehicle?

Go to Step 2

Go to
Diagnostic
System Check -
Vehicle

2

Verify that the front fog lamps are
inoperative.
Do the front fog lamps operate normally?

Go to Testing
for Intermittent
Conditions and
Poor
Connections

Go to Step 3

3

Is only one front fog lamp inoperative?

Go to Step 4

Go to Step 5

4

1. Inspect the inoperative bulb and

socket for an open filament or poor
terminal contact and replace as
necessary. Refer to Front Fog Lamp
Bulb Replacement.

2. If a condition is not found, locate and

repair the open or high resistance in
the front fog lamp supply voltage
circuit or ground circuit to the
inoperative lamp. Refer to Circuit
Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 16

-

5

With the engine OFF, turn the key to RUN
and the headlamp switch to PARK.
Do the park lamps illuminate?

Go to Step 6

Go to
Symptoms -
Lighting
Systems

6

Inspect the FOG LP fuse.
Is the fuse open?

Go to Step 7

Go to Step 8

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Lighting - H3

7

Test for a short to ground in the front fog
lamp supply voltage circuit. Refer to
Circuit Testing and Wiring Repairs .
Did you find and correct a condition?

Go to Step 16

Go to Step 14

8

1. Place the front fog lamp switch in the

ON position.

2. Remove the front fog lamp relay.

Refer to Relay Replacement
(Attached to Wire Harness) or
Relay Replacement (Within an
Electrical Center) .

3. Test for a voltage signal at the fog

lamp relay control circuit terminal for
the front fog lamp relay in the
underhood fuse block. Refer to
Electrical Center Identification
Views and Circuit Testing .

Was a voltage signal present?

Go to Step 11

Go to Step 9

9

Test the front fog lamp switch signal and
ground circuits for an open, high resistance
or short to voltage. Refer to Circuit
Testing and Wiring Repairs .
Did you find and correct a condition?

Go to Step 16

Go to Step 10

10

1. Remove the fog lamp switch. Refer to

Headlamp Switch Replacement.

2. Place a fused jumper between the fog

lamp switch signal and ground
connector terminals.

3. Test for a voltage signal at the fog

lamp relay control circuit terminal for
the front fog lamp relay in the
underhood fuse block. Refer to
Electrical Center Identification
Views and Circuit Testing .

Was a voltage signal present?

Go to Step 15

Go to Step 12

Test for an open or high resistance in the

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Lighting - H3

REAR FOG LAMPS ALWAYS ON

Rear Fog Lamps Always On

11

front fog lamp supply voltage circuit and
fog lamp ground circuit. Refer to Circuit
Testing and Wiring Repairs .
Did you find and correct a condition?

Go to Step 16

Go to Step 14

12

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

Go to Step 16

Go to Step 13

13

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

Go to Step 16

-

14

Replace the front fog lamp relay. Refer to
Relay Replacement (Attached to Wire
Harness) or Relay Replacement (Within
an Electrical Center) .
Did you complete the repair?

Go to Step 16

-

15

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

Go to Step 16

-

16

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 3

Step

Action

Yes

No

Schematic Reference: Fog Lights Schematics
Connector End View Reference: Lighting Systems Connector End Views or Data
Communication Connector End Views

1

Did you perform the Diagnostic System
Check - Vehicle?

Go to

Diagnostic

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Lighting - H3