Hummer H3. Manual — part 1298

Did you find and correct the
condition?

Go to Step 21

Go to Heating
Performance
Diagnostic

9

Test the position signal circuit of
the appropriate temperature
actuator for an open or for a high
resistance. Refer to Circuit
Testing and Wiring Repairs .
Did you find and correct the
condition?

-

Go to Step 21 Go to Step 10

10

Test the low reference circuit of
the appropriate temperature
actuator for an open or for a high
resistance. Refer to Circuit
Testing and Wiring Repairs .
Did you find and correct the
condition?

-

Go to Step 21 Go to Step 11

11

Test the 5-volt reference circuit of
the appropriate air temperature
actuator for a high resistance.
Refer to Circuit Testing and
Wiring Repairs .
Did you find and correct the
condition?

-

Go to Step 21 Go to Step 12

12

1. Turn OFF the ignition.

2. Reconnect the appropriate

temperature actuator.

3. Turn ON the ignition with

the engine OFF.

4. Connect a test lamp between

temperature door control A
and temperature door control
B circuits of the appropriate
temperature actuator
connector.

5. Place the temperature switch

in the cold position.

6. Place the temperature switch

-

2007 Hummer H3

2007 HVAC HVAC - Manual - H3

in the hot position.

Does the test lamp illuminate in
both positions?

Go to Step 21 Go to Step 13

13

Test the temperature door control
A and temperature door control B
circuits of the appropriate
temperature actuator for an open, a
high resistance, a short to ground
or a short to voltage. Refer to
Circuit Testing and Wiring
Repairs .
Did you find and correct the
condition?

-

Go to Step 21 Go to Step 14

14

Test the ignition 3 voltage circuit
of the HVAC control module for
an open or for a high resistance.
Refer to Circuit Testing and
Wiring Repairs .
Did you find and correct the
condition?

-

Go to Step 15 Go to Step 17

15

Test the ground circuit of the
HVAC control module for an open
or for a high resistance. Refer to
Circuit Testing and Wiring
Repairs .
Did you find and correct the
condition?

-

Go to Step 16 Go to Step 18

16

Inspect the appropriate air
temperature door for a mechanical
condition or for a condition that
allows excessive travel of the
door.
Did you complete the repair?

-

Go to Step 21

-

17

Inspect for poor connections at the
harness connector of the
appropriate air temperature
actuator. Refer to Testing for
Intermittent Conditions and

-

2007 Hummer H3

2007 HVAC HVAC - Manual - H3

Poor Connections and
Connector Repairs .
Did you find and correct the
condition?

Go to Step 21 Go to Step 19

18

Inspect for poor connections at the
harness connector of the HVAC
control module. Refer to Testing
for Intermittent Conditions and
Poor Connections and
Connector Repairs .
Did you find and correct the
condition?

-

Go to Step 21 Go to Step 20

19

Replace the appropriate air
temperature door actuator. Refer
to Air Temperature Actuator
Replacement - Right Side (Left
Hand Drive). Air Temperature
Actuator Replacement - Right
Side (Right Hand Drive), Air
Temperature Actuator
Replacement - Left Side (Left
Hand Drive) or Air
Temperature Actuator
Replacement - Left Side (Right
Hand Drive).Did you complete
the replacement?

IMPORTANT:

Perform the calibration procedure for
the air temperature actuator.

-

Go to Step 21

-

20

Replace the HVAC control
module. Refer to Heater and Air
Conditioning Control
Replacement.
Did you complete the
replacement?

-

Go to Step 21

-

21

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

-

System OK

Go to Step 2

2007 Hummer H3

2007 HVAC HVAC - Manual - H3

AIR DELIVERY IMPROPER

Test Description

The numbers below refer to the step numbers on the diagnostic table.

13: The test lamp should illuminate while trying to command the mode door in both
directions.

15: Two voltage circuits supply the HVAC control assembly.

Air Delivery Improper

Step

Action

Yes

No

Schematic Reference: HVAC Schematics
Connector End View Reference: HVAC Connector End Views
DEFINITION: Air does not flow correctly from the air distribution outlets.

1

Did you perform the Diagnostic System
Check - Vehicle?

Go to Step 2

Go to Diagnostic
System Check -
Vehicle

2

1. Turn ON the ignition, with the

engine OFF.

2. Place the blower motor switch in the

OFF position.

Is the blower motor OFF?

Go to Step 3

Go to Blower
Motor
Malfunction

3

Place the blower motor switch in each
speed position.
Does the blower motor operate in any
speed position?

Go to Step 4

Go to Blower
Motor
Malfunction

4

Does the blower motor operate in each
speed position?

Go to Step 5

Go to Blower
Motor
Malfunction

5

Are all of the HVAC control assembly
controls except for the blower motor
inoperative?

Go to Step 15

Go to Step 6

1. Place the blower motor switch in the

maximum speed position.

2. Place the mode switch in the vent

position.

2007 Hummer H3

2007 HVAC HVAC - Manual - H3