Mazda CX-9 Grand Touring. Manual — part 440

NO.6 INSUFFICIENT AIR (OR NO AIR) BLOWN REAR VENTS

NO.6 INSUFFICIENT AIR (OR NO AIR) BLOWN REAR VENTS DESCRIPTION AND POSSIBLE
CAUSE

DIAGNOSTIC PROCEDURE

*11

INSPECT WIRING HARNESS BETWEEN FRONT
CLIMATE CONTROL UNIT AND AIR INTAKE
ACTUATOR FOR SHORT TO B+



Turn the ignition switch to the ON position



Measure the voltage at the following front climate
control unit terminals.



Terminal 10 (RECIRCULATE signal)



Terminal 1M (FRESH signal)



Is the voltage approx. 12 V?

Yes

Repair the wiring harness between
the front climate control unit and air
intake actuator, then go to Step 14.

No

Replace the front climate control

unit, then go to Step 14.

12

INSPECT A/C UNIT AIR INTAKE DOOR



Is there any foreign material or obstruction in the
A/C unit air intake door?

Yes

Remove obstruction, then go to
Step 14.

No

Go to the next step.

13

VERIFY THAT A/C UNIT AIR INTAKE DOOR IS
POSITIONED SECURELY AND PROPERLY



Is the A/C unit air intake door securely and
properly positioned?

Yes

Inspect the air intake door for
cracks or damage, then go to the
next step.

No

Install the air intake door securely

in the proper position, then go to

the next step.

14

VERFY REPAIR



Does the malfunction disappear?

Yes

Troubleshooting completed.
Explain repairs to customer.

No

Recheck malfunction symptoms,

then repeat from Step 1 if the

malfunction recurs.

6

Insufficient air (or no air) from rear vents

DESCRIPTION



Problem with each rear vent and/or duct



Rear airflow mode does not change when front and/or rear climate control
unit mode switches.

POSSIBLE

CAUSE



Rear vent mode malfunction



Rear heat mode malfunction



Rear airflow mode actuator malfunction



Open, short circuit in wiring or poor connection between front and rear
climate control unit

2008 Mazda CX-9 Grand Touring

2008 HVAC Symptom Troubleshooting (HVAC) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:14:50 AM

Page 16

© 2005 Mitchell Repair Information Company, LLC.

NO.6 INSUFFICIENT AIR (OR NO AIR) BLOWN REAR VENTS DIAGNOSTIC PROCEDURE

STEP

INSPECTION

ACTION

1

INSPECT TO SEE WHETHER MALFUNCTION IS IN
VENT MODE



Does air blow out when in the rear vent mode?

Yes Go to the Step 6.

No

Go to the next step.

2

VERIFY THAT REAR HEATER CONTROL USING
FRONT CLIMATE CONTROL UNIT



Turn the rear heater to ON and OFF using the front A/C
control panel.



Is it possible that the rear heater turns ON and OFF using
the front climate control unit?

Yes Go to Step 4.

No

Go to the next step.

3

INSPECT TO SEE WHETHER MALFUNCTION IS IN
WIRING HARNESS (OPEN, SHORT OR POOR
CONNECTION OF TERMINALS BETWEEN FRONT
AND REAR CLIMATE CONTROL UNIT) OR
ELSEWHERE



Inspect for open, short or poor connection of terminals
between front and rear climate control unit.



Terminal 3E (front)-terminal A (rear)



Terminal 3G (front)-terminal C (rear)



Terminal 3H (front)-terminal D (rear)



Terminal 31 (front)-terminal E (rear)



Terminal 3C (front)-terminal F (rear)



Is there any open, short or poor connection of terminals?

Yes

Repair or replace
malfunctioning part, then go
to Step 10.

No

Go to the next step.

4

INSPECT VENT



Is the vent clogged?

Yes

Remove obstruction, then go
to Step 10.

No

Go to the next step.

5

VERIFY THAT REAR A/C DUCT IS INSTALLED



Is the rear A/C duct properly installed?

Yes

Inspect the duct for
clogging, deformation and
air leakage, then go to Step
10.

No

Install the duct securely in

the proper position, then go

to Step 10.

6

INSPECT TO SEE WHETHER MALFUNCTION IS IN
REAR HEAT MODE



Does air blow out when in the rear heat mode?

Yes Go to the next step.

No

Inspect the rear vent for

clogging, then go to Step 10.

7

INSPECT REAR VENT



Is the rear vent clogged?

Yes

Remove obstruction, then go
to Step 10.

No

Go to the next step.

2008 Mazda CX-9 Grand Touring

2008 HVAC Symptom Troubleshooting (HVAC) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:14:51 AM

Page 17

© 2005 Mitchell Repair Information Company, LLC.

NO.7 AMOUNT OF AIR FROM REAR VENTS DOES NOT CHANGE

NO.7 AMOUNT OF AIR FROM REAR VENTS DOES NOT CHANGE DESCRIPTION AND
POSSIBLE CAUSE

8

INSPECT REAR MODE ACTUATOR



(See REAR AIRFLOW MODE ACTUATOR
INSPECTION .)



Is the rear airflow mode actuator normal?

Yes Go to the next step.

No

Replace the rear airflow

mode actuator, then go to

Step 10.

9

INSPECT TO SEE WHETHER MALFUNCTION IS IN
WIRING HARNESS (OPEN, SHORT OR POOR
CONNECTION OF TERMINALS BETWEEN FRONT
AND REAR AIRFLOW MODE ACTUATOR) OR
ELSEWHERE



Inspect for open, short or poor connection of terminals
between front and rear airflow mode actuator.



Terminal 2P (front climate control unit)- terminal C
(rear airflow mode actuator)



Terminal 2B (front climate control unit)- terminal A
(rear airflow mode actuator)



Terminal 2D (front climate control unit)- terminal E
(rear airflow mode actuator)



Terminal 1N (front climate control unit)- terminal F
(rear airflow mode actuator)



Terminal 1L (front climate control unit)- terminal G
(rear airflow mode actuator)



Is there any open, short or poor connection of terminals?

Yes

Repair or replace
malfunctioning part, then go
to next step.

No

Replace the front climate

control unit, go to the next

step.

10

VERIFY REPAIR



Does air blow from the rear A/C vent mode?

Yes

Troubleshooting completed.
Explain repairs to customer.

No

Recheck malfunction

symptoms, then repeat from

Step 1 if the malfunction

recurs.

7

Amount of air from rear vents does not change

DESCRIPTION



Malfunction in rear blower motor system



Amount of air blowing rear vents does not change when switching front and/or
rear climate control unit airflow volume control dial.

POSSIBLE

CAUSE



Rear A/C unit malfunction



Rear blower motor malfunction



Rear power MOS FET malfunction

2008 Mazda CX-9 Grand Touring

2008 HVAC Symptom Troubleshooting (HVAC) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:14:51 AM

Page 18

© 2005 Mitchell Repair Information Company, LLC.



When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors
while doing the inspection to discover whether poor contact points are the cause of any intermittent
malfunctions. If there is a problem, inspect to make sure connectors, terminals and wiring harness are
connected correctly and undamaged.

DIAGNOSTIC PROCEDURE

NO.7 AMOUNT OF AIR FROM REAR VENTS DOES NOT CHANGE DIAGNOSTIC PROCEDURE



Rear climate control unit malfunction

STEP

INSPECTION

ACTION

1

INSPECT TO SEE WHETHER MALFUNCTION
IS IN REAR A/C UNIT OR ELSEWHERE



Turn the ignition switch to the ON position.



Turn the rear fan switch the ON position.



Does the blower motor rotate smoothly?

Yes Go to the next step.

No

Go to Step 3.

2

INSPECT REAR A/C UNIT INTAKE VENT



Is the rear A/C unit intake vent clogged?

Yes

Remove obstruction, then go to Step
13.

No

Inspect if there are any obstructions

in the rear A/C unit passage, then go

to Step 13.

3*

INSPECT TO SEE WHETHER MALFUNCTION
IS IN REAR BLOWER RELAY SYSTEM OR
REAR POWER MOS FET



Turn the ignition switch to ON position.



Turn the rear fan switch to OFF position.



Measure the voltage at the following rear blower
motor terminal.



Terminal B (rear blower motor operation
signal)



Is the voltage normal (B+)?

Yes Go to the Step 7.

No

Go to the next step.

4*

INSPECT TO SEE WHETHER MALFUNCTION
IS IN WIRING HARNESS (OPEN OR SHORT
CIRCUIT BETWEEN FUSE BLOCK AND REAR
BLOWER RELAY) OR ELSEWHERE



Measure the voltage at the following rear relay
terminals.



Terminal A (IG2 signal)



Terminal D (B+ signal)



Is the voltage approx. 12 V?

Yes Go to the next step.

No

If the terminal A voltage is not

normal, repair or replace wiring

harness between A/C 7.5 A fuse and

rear blower relay.

If the terminal D voltage is not

normal, repair or replace wiring

harness between R.HEATER 40 A

fuse and rear blower relay. Then go

to Step 13.

2008 Mazda CX-9 Grand Touring

2008 HVAC Symptom Troubleshooting (HVAC) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:14:51 AM

Page 19

© 2005 Mitchell Repair Information Company, LLC.