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.