Hummer H3. Manual — part 1422

INTERIOR BACKLIGHTING DOES NOT DIM

Interior Backlighting Does Not Dim

properly?

Go to Step 4 Systems

4

1. Place the turn signal/multifunction

switch to the low beams position.

2. Using a scan tool, select the IPC

Special Functions Display Test to
command the high beam indicator
ON, then OFF.

Does the high beam indicator lamp turn
ON and OFF when commanded?

Go to Testing
for Intermittent
Conditions and
Poor
Connections

Go to Step 5

5

Inspect for poor connections at the harness
connector of the instrument panel cluster
(IPC). Refer to Circuit Testing and
Wiring Repairs
Did you find and correct the condition?

Go to Step 7

Go to Step 6

6

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

Go to Step 7

-

7

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: Interior Lights Dimming 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

Verify that the interior backlighting does

Go to Testing

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Lighting - H3

INTERIOR BACKLIGHTING INOPERATIVE

2

not dim.
Does the interior backlighting operate
normally?

for Intermittent

Conditions and

Poor

Connections

Go to Step 3

3

Use the scan tool to observe the Dimming
Potentiometer voltage data in the body
control module (BCM) Data List while
adjusting the dimmer switch throughout the
full range.
Does the scan tool data indicate an
approximate voltage change from the
minimum to the maximum voltage?

Go to Step 6

Go to Step 4

4

Test for a short to ground in the instrument
panel lamps dimming signal circuit. Refer
to Circuit Testing and Wiring Repairs .
Did you find and correct a condition?

Go to Step 9

Go to Step 5

5

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

Go to Step 9

Go to Step 8

7

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

Go to Step 9

-

8

Replace the BCM. Refer to Control
Module References for replacement, setup
and programming.
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

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Lighting - H3

Interior Backlighting Inoperative

Step

Action

Yes

No

Schematic Reference: Interior Lights Dimming Schematics
Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System
Check - Vehicle?

Go to Step 2

Go to
Diagnostic
System Check -
Vehicle

2

Verify that the interior backlighting is
inoperative.
Does the interior backlighting operate
normally?

Go to Testing
for Intermittent
Conditions and
Poor
Connections

Go to Step 3

3

Do the park lamps operate correctly?

Go to Step 4

Go to
Symptoms -
Lighting
Systems

4

Are all of the interior backlighting lamps
inoperative?

Go to Step 7

Go to Step 5

5

Test for an open or high resistance in the
following circuits of the inoperative lamp.
Refer to Circuit Testing and Wiring
Repairs .

The instrument panel lamps supply
voltage

The park lamp supply voltage

The ground

Did you find and correct a condition?

Go to Step 10

Go to Step 6

6

Connect a test lamp between the supply
voltage circuit and ground circuit of the
inoperative lamp. Refer to Wiring
Repairs .
Does the test lamp illuminate?

Go to Step 8

Go to Step 7

Inspect for poor connections at the harness
connector of the body control module

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Lighting - H3

LICENSE LAMPS INOPERATIVE

License Lamps Inoperative

7

(BCM). Refer to Circuit Testing and
Wiring Repairs .
Did you find and correct the condition?

Go to Step 10

Go to Step 9

8

Replace the affected lamp or internal lamp
component.
Did you complete the replacement?

Go to Step 10

-

9

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

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: Exterior Lights Schematics
Connector End View Reference: Lighting Systems 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 license lamps are
inoperative.
Do the license lamps operate normally?

Go to Testing
for Intermittent
Conditions and
Poor
Connections

Go to Step 3

3

Is the right tail lamp inoperative also?

Go to Step 5

Go to Step 4

4

Inspect the inoperative bulbs/sockets for
open filaments or poor terminal contact.
Does any lamp have an open filament or
poor terminal contact?

Go to Step 7

Go to Step 6

5

Repair the open, high resistance or short to
ground in the park lamp supply voltage
circuit. Refer to Wiring Repairs .
Did you complete the repair?

Go to Step 8

-

2007 Hummer H3

2007 ACCESSORIES & EQUIPMENT Lighting - H3