Mazda CX-9 Grand Touring. Manual — part 432

3G

Rear
temperature
control volume

Rear climate
control unit

Moving towards
COLD

less

continuity, short circuit
(Front climate control
unit-rear airflow mode
actuator: 3G-C)



Rear climate control
unit



Front climate control
unit: terminal voltage
(2B)

Temperature control
dial (rear side):
Moving towards
medium
temperature

Approx.
2.5

Temperature control
dial (rear side):
Moving towards
HOT

Approx.

4.2

3H

+5 V

Rear climate
control unit

Under any
condition

5.0



Wiring harness:
continuity (Front
climate control unit-
ground: 3H-ground)

3I

Ground

Rear climate
control unit

Under any
condition: Inspect
for continuity to
ground

1.0 or

less



Wiring harness:
continuity (Front
climate control unit-
rear climate control
unit: 31-E)

3J

Panel light
control input

Instrument cluster

Turn the headlight
switch to the off
position

1.0 or

less



Wiring harness:
continuity, short circuit
(Front climate control
unit-instrument cluster:
3J-1I)



TNS relay



Headlight switch

Turn the headlight
switch to the TNS
position

B+

2008 Mazda CX-9 Grand Touring

2008 HVAC Control System (HVAC) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:12:36 AM

Page 46

© 2005 Mitchell Repair Information Company, LLC.

Fig. 58: Temperature Sensors Graph Chart
Courtesy of MAZDA MOTORS CORP.

REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION

1. Disconnect the negative battery cable.

2. Remove the console cover. (See CONSOLE COVER REMOVAL/INSTALLATION .)

3. Remove the rear cooler duct. (See REAR COOLER DUCT REMOVAL/INSTALLATION .)

4. Remove the screws.

5. Remove the rear climate control unit.

6. Install in the reverse order of removal.

Fig. 59: Identifying Rear Climate Control Unit & Screws

2008 Mazda CX-9 Grand Touring

2008 HVAC Control System (HVAC) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:12:36 AM

Page 47

© 2005 Mitchell Repair Information Company, LLC.

Courtesy of MAZDA MOTORS CORP.

REAR CLIMATE CONTROL UNIT INSPECTION

1. Connect the rear climate control unit connector.

2. Turn the ignition switch to the ON position.

3. Connect the negative (-) lead of the tester to body ground.

4. By inserting the positive (+) lead of the tester into each rear climate control unit terminal, measure the

voltage according to the terminal voltage table.



If there is any malfunction, inspect the parts under "Inspection item (s)".



If the parts under "Inspection item (s)" are found to be normal, replace the rear climate
control unit.

TERMINAL VOLTAGE TABLE (REFERENCE)

Fig. 60: Identifying Rear Climate Control Unit Terminals
Courtesy of MAZDA MOTORS CORP.

TERMINAL VOLTAGE REFERENCE

Terminal

Signal name

Connected to

Measurement condition

Voltage (V)

Inspection item

(s)

A

Rear fan
control volume

Front climate
control unit

Airflow
volume
control dial

Off

1.0 or less



Front
climate
control
unit:
terminal
voltage
(1T)



Wiring
harness:
continuity,
short
circuit
(Front
climate
control

1st.

Approx. 1.3

2008 Mazda CX-9 Grand Touring

2008 HVAC Control System (HVAC) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:12:36 AM

Page 48

© 2005 Mitchell Repair Information Company, LLC.

Max HI

Approx. 4.0

unit-rear
climate
control
unit: 3E-
A)



Rear
climate
control
unit

B

-

-

-

-

-

C

Rear
temperature
control volume

Front climate
control unit

Temperature control dial:
Moving towards COLD

1.0 or less



Wiring
harness:
continuity,
short
circuit
(Front
climate
control
unit-rear
airflow
mode
actuator:
3G-C)



Rear
climate
control
unit



Front
climate
control
unit:
terminal
voltage
(2B)

Temperature control dial:
Moving towards medium
temperature

Approx. 2.5

Temperature control dial:
Moving towards HOT

Approx. 4.2

D

+5V

Front climate
control unit

Under any condition

5.0



Front
climate
control
unit:
terminal
voltage
(3H)



Wiring
harness:
continuity
(Front

2008 Mazda CX-9 Grand Touring

2008 HVAC Control System (HVAC) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:12:36 AM

Page 49

© 2005 Mitchell Repair Information Company, LLC.