Hummer H2. Manual — part 696

3

the inside rearview mirror.

2. Cover the sensor on the inside rearview mirror

back, facing the front window.

3. Shine a bright light into the sensor on the

inside rearview mirror face, facing the rear
window.

Does the inside rearview mirror darken?

-

Go to Step 4

Go to Step 5

4

While shining a bright light into the sensor on the
mirror face, facing the rear window, observe the
driver outside rearview mirror.
Does the driver outside rearview mirror darken?

-

Go to Testing for

Intermittent

Conditions and

Poor Connections

in Wiring Systems

Go to Step 9

5

1. Turn OFF the ignition.

2. Disconnect the harness connector of the inside

rearview mirror.

3. Measure the resistance between the ground

circuit of the inside rearview mirror and a
good ground.

Is the resistance less than the specified value?

3 ohm

Go to Step 6

Go to Step 18

6

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

2. Measure the voltage between the ignition

voltage circuit and the ground circuit of the
inside rearview mirror.

Is the voltage within the specified range?

B+

Go to Step 7

Go to Step 19

7

1. Place the transmission in PARK.

2. Measure the voltage between the backup lamp

supply voltage circuit and the ground circuit of
the inside rearview mirror.

Is the voltage less than the specified value?

0.5 V

Go to Step 8

Go to Backup

Lamps Always

On in Lighting

Systems

8

1. Place the transmission in REVERSE.

2. Measure the voltage between the backup lamp

supply voltage circuit and the ground circuit of
the inside rearview mirror.

Is the voltage within the specified range?

B+

Go to Step 15

Go to Step 12

1. Turn OFF the ignition.

2. Disconnect the harness connector C2 of the

driver door module (DDM).

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Stationary Windows - Hummer H2

9

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

4. Turn ON the automatic day-night feature of

the inside rearview mirror.

5. Cover the sensor on the mirror back, facing the

front window.

6. Shine a bright light into the sensor on the

mirror face, facing the rear window.

7. Measure the voltage between the automatic

day-night signal circuit and the low reference
circuit of the driver outside mirror element.

Is the voltage within the specified range?

0.75-

1.5 V

Go to Step 11

Go to Step 10

10

Measure the voltage between the automatic day-
night signal circuit of the driver outside mirror
element and a good ground.
Is the voltage within the specified range?

0.75-

1.5 V

Go to Step 14

Go to Step 13

11

1. Turn OFF the ignition.

2. Disconnect the harness connector C3 of the

DDM.

3. Connect a 3-ampere fused jumper wire

between harness connectors C2 and C3 for the
automatic day-night signal circuit of driver
outside rearview mirror element.

4. Connect a 3-ampere fused jumper wire

between harness connectors C2 and C3 for the
low reference circuit of driver outside rearview
mirror element.

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

6. Turn ON the automatic day-night feature of

the inside rearview mirror.

7. Cover the sensor on the mirror back, facing the

front window.

8. Shine a bright light into the sensor on the

mirror face, facing the rear window.

9. While shining a bright light into the sensor on

the mirror face, facing the rear window,
observe the driver outside rearview mirror.

Does the driver outside rearview mirror darken?

-

Go to Step 16

Go to Step 17

12

Test the backup lamp supply voltage circuit of the
inside rearview mirror for an open or short to
ground. Refer to Circuit Testing and Wiring
Repairs in Wiring Systems.

-

Go to Backup

Lamps

Inoperative in

Lighting

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Stationary Windows - Hummer H2

Did you find and correct the condition?

Go to Step 24

Systems

13

Test the automatic day-night signal circuit of the
driver outside rearview mirror element for an open or
short to ground. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.
Did you find or correct the condition?

-

Go to Step 24

Go to Step 15

14

Test the low reference circuit of the driver outside
rearview mirror element for an open or high
resistance. Refer to Circuit Testing and Wiring
Repairs in Wiring Systems.
Did you find or correct the condition?

-

Go to Step 24

Go to Step 15

15

Inspect for poor connections at the harness connector
of the inside rearview mirror. 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 24

Go to Step 21

16

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

-

Go to Step 24

Go to Step 22

17

Inspect for poor connections at the harness connector
of the driver outside rearview mirror. Refer to
Testing for Intermittent Conditions and Poor
Connections and Connector Repairs in Wiring
Systems.
Did you find or correct the condition?

-

Go to Step 24

Go to Step 23

18

Repair an open or high resistance in the ground
circuit of the inside rearview mirror. Refer to Wiring
Repairs in Wiring Systems.
Did you complete the repair?

-

Go to Step 24

-

19

Repair an open or short to ground in the ignition
voltage circuit of the inside rearview mirror. Refer to
Wiring Repairs in Wiring Systems.
Did you complete the repair?

-

Go to Step 24

-

1. Repair a short to voltage on the automatic day-

night signal circuit of the driver outside

IMPORTANT:

A short to voltage on the automatic day-night
signal circuit of the driver outside rearview mirror
element will cause permanent damage to the
driver outside rearview mirror and the inside
rearview mirror. Both mirrors will have to
replaced. The following actions will need to be
performed:

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Stationary Windows - Hummer H2

MIRRORS - TEMPERATURE DISPLAY INACCURATE

Diagnostic Aids

z

An inaccurate temperature display indicates an abnormal resistance condition within the system.

z

For intermittent diagnosis, refer to Testing for Intermittent Conditions and Poor Connections in
Wiring Systems.

The following table will be used to measure the resistance of the sensor and compare it with the actual ambient
temperature. The mirror's temperature accuracy should be within 5 degrees of the actual temperature. The actual
temperature should not be taken from a radio station, a sign displaying the temperature, etc. A temperature
measuring tool such as a thermometer should be used. Some temperature measuring tools may be within 5
degrees of the actual temperature. Make sure to consult the manufacturer for the accuracy of the tool. This

20

rearview mirror element. Refer to Wiring
Repairs in Wiring Systems.

2. Replace the inside rearview mirror and the

driver outside rearview mirror. Refer to the
following:

z

Mirror Replacement in Doors

z

Rearview Mirror Replacement

Did you complete the repair?

IMPORTANT:

Perform the Compass Calibration and
Variance Procedure for the inside rearview
mirror with compass.

-

Go to Step 24

-

21

Replace the inside rearview mirror. Refer to
Rearview Mirror Replacement .Did you complete
the replacement?

IMPORTANT:

Perform the Compass Calibration and Variance
Procedure for the inside rearview mirror with
compass.

-

Go to Step 24

-

22

Replace the DDM. Refer to Switch Replacement -
Door Lock and Side Window - Driver .
Is the replacement complete?

-

Go to Step 24

-

23

Replace the driver outside rearview mirror. Refer to
Mirror Replacement .
Did you complete the replacement?

-

Go to Step 24

-

24

Operate the system in order to verify the repair.
Did you correct the condition?

-

System OK

Go to Step 2

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Stationary Windows - Hummer H2