Mazda CX-9 Grand Touring. Manual — part 438

NO.3 AIR INTAKE MODE FROM FRONT VENT DOES NOT CHANGE

NO.3 AIR INTAKE MODE FROM FRONT VENT DOES NOT CHANGE DESCRIPTION AND
POSSIBLE CAUSE



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.

13*

FRONT POWER MOS FET AND FRONT CLIMATE
CONTROL UNIT) OR ELSEWHERE



Turn the ignition switch to the LOCK position.



Disconnect front climate control unit connector.



Inspect for continuity at the following terminals
between the front power MOS FET and front climate
control unit.



Terminal F-1R (blower motor control signal)



Terminal B-1P (blower motor feedback signal)



Is there continuity?

No

Repair the wiring harness

between the front power MOS

FET and climate control unit,

then go to Step 15.

14*

INSPECT TO SEE WHETHER MALFUNCTION IS IN
CLIMATE CONTROL UNIT OR WIRING HARNESS
(SHORT TO GROUND IN WIRING HARNESS
BETWEEN FRONT POWER MOS FET AND FRONT
CLIMATE CONTROL UNIT)



Inspect for continuity at the following terminal between
the power MOS FET and ground.



Terminal D (blower motor control signal)- ground



Is there continuity?

Yes

Repair the wiring harness
between the front power MOS
FET and ground, then go to the
next step.

No

Replace the front climate

control unit, then go to the next

step.

15

VERIFY REPAIR



Is air discharged from vent?

Yes

Troubleshooting completed.
Explain repairs to customer.

No

Recheck malfunction

symptoms, then repeat from

Step 1 if the malfunction

recurs.

3

Air intake mode from front vent does not change.

DESCRIPTION



Malfunction in A/C unit and/or front climate control unit air intake mode
switching system



Air intake mode does not change when switching REC/FRESH mode.

POSSIBLE

CAUSE



Air intake actuator malfunction



Air intake door malfunction

2008 Mazda CX-9 Grand Touring

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

Microsoft

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

Page 8

© 2005 Mitchell Repair Information Company, LLC.

DIAGNOSTIC PROCEDURE

NO.3 AIR INTAKE MODE FROM FRONT VENT DOES NOT CHANGE DIAGNOSTIC
PROCEDURE

STEP

INSPECTION

ACTION

1

INSPECT AIR INTAKE ACTUATOR



Is the air intake actuator normal?

Yes Go to the next step.

No

Replace the air intake actuator,

then go to Step 9.

2*

INSPECT TO SEE WHETHER MALFUNCTION
(OPEN OR SHORT CIRCUIT) IS IN AIR INTAKE
ACTUATOR, WIRING HARNESS (BETWEEN
CLIMATE CONTROL UNIT AND AIR INTAKE
ACTUATOR) OR ELSEWHERE



Turn the ignition switch to the ON position.



Measure the voltages at the following climate control
unit terminals.



Terminal 1O (24-pin, RECIRCULATE motor
drive signal)



Terminal 1M (24-pin, FRESH motor drive
signal)

(See FRONT CLIMATE CONTROL UNIT
INSPECTION .)



Are voltages normal?

Yes Go to the next step.

No

Go to Step 4.

3*

INSPECT TO SEE WHETHER MALFUNCTION
(OPEN OR SHORT CIRCUIT) IS IN AIR INTAKE
ACTUATOR OR WIRING HARNESS (BETWEEN
CLIMATE CONTROL UNIT AND AIR INTAKE
ACTUATOR)



Measure the voltages at the following air intake
actuator terminals.



Terminal C (RECIRCULATE motor drive
signal)



Terminal A (FRESH motor drive signal)



Are voltages as shown below?



Terminal C: approx. 0.5 V during FRESH and
approx. 10 V during RECIRCULATE



Terminal A: approx. 10 V during FRESH and
approx. 0.5 V during RECIRCULATE

Yes Go to Step 7.

No

Repair the wiring harness

between the climate control unit

and air intake actuator, then go

to Step 9.

INSPECT TO SEE WHETHER MALFUNCTION IS IN
AIR INTAKE ACTUATOR OR ELSEWHERE

2008 Mazda CX-9 Grand Touring

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

Microsoft

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

Page 9

© 2005 Mitchell Repair Information Company, LLC.

4



Disconnect the air intake actuator connector.



Measure the voltages at the following climate control
unit terminals.



Terminal 10 (RECIRCULATE motor drive
signal)



Terminal 1M (FRESH motor drive signal) (See
FRONT CLIMATE CONTROL UNIT
INSPECTION .)



Are voltages normal?

Yes

Inspect the air intake actuator,
then go to Step 9.

No

Go to the next step.

5

INSPECT TO SEE WHETHER MALFUNCTION IS IN
WIRING HARNESS (SHORT TO B+ BETWEEN
CLIMATE CONTROL UNIT AND AIR INTAKE
ACTUATOR) OR ELSEWHERE



Disconnect the climate control unit connector.



Measure the voltages at the following climate control
unit terminals.



Terminal 1O (RECIRCULATE motor drive
signal)



Terminal 1M (FRESH motor drive signal)



Are voltages approx. 0 V?

Yes Go to the next step.

No

Repair the wiring harness

between the climate control unit

and air intake actuator, then go

to Step 9.

6

INSPECT TO SEE WHETHER MALFUNCTION IS IN
WIRING HARNESS (SHORT TO GROUND
BETWEEN CLIMATE CONTROL UNIT AND AIR
INTAKE ACTUATOR) OR ELSEWHERE



Turn the ignition switch to the LOCK position.



Inspect for continuity at the following terminals
between the climate control unit and ground.



Terminal 10 (RECIRCULATE motor drive
signal)



Terminal 1M (FRESH motor drive signal)



Is there continuity?

Yes

Repair the wiring harness
between the climate control unit
and air intake actuator, then go
to Step 9.

No

Go to the next step.

7

INSPECT AIR INTAKE LINK



Inspect the air intake links for followings:



is there grease on link?



Are the links securely and properly installed?



Are the links free of obstructions and
hindrances?



Are the above items normal?

Yes Go to the next step.

No

Apply grease to the links. If any

the links are damaged, replace

the air intake actuator, then go to

Step 9.

INSPECT TO SEE WHETHER MALFUNCTION IS IN

2008 Mazda CX-9 Grand Touring

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

Microsoft

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

Page 10

© 2005 Mitchell Repair Information Company, LLC.

NO.4 NO TEMPERATURE CONTROL WITH FRONT CLIMATE CONTROL
UNIT

NO.3 AIR INTAKE MODE FROM FRONT VENT DOES NOT CHANGE DESCRIPTION AND
POSSIBLE CAUSE

DIAGNOSTIC PROCEDURE

NO.3 AIR INTAKE MODE FROM FRONT VENT DOES NOT CHANGE DIAGNOSTIC
PROCEDURE

8

CLIMATE CONTROL UNIT OR AIR INTAKE DOOR



Inspect the A/C unit air intake door.



Is the door free of obstructions, cracks, and
damage?



Are the doors securely and properly installed?



Are the above items normal?

Yes

Replace the climate control unit,
then go to the next step.

No

Remove obstruction, or install

the doors in the proper position.

If any doors are cracked or

damaged, replace them, then go

to the next step.

9

VERIFY REPAIR



Does the air intake mode change smoothly?

Yes

Troubleshooting completed.
Explain repairs to customer.

No

Recheck malfunction symptoms,

then repeat from Step 1 if the

malfunction recurs.

4

No temperature control with front climate control unit

DESCRIPTION



Malfunction in A/C unit and/or front climate control unit air mix system



Temperature does not change when switching front climate control unit
temperature setting dial.

POSSIBLE

CAUSE



A/C unit air intake link, air intake crank, air intake rod, air intake wire, wire
clamp malfunction



Climate control unit rack-and-pinion, air intake wire malfunction



A/C unit air intake door malfunction



Heater piping malfunction

STEP

INSPECTION

ACTION

1

INSPECT COOLANT TEMPERATURE



Is the engine at operating temperature?

Yes Go to the next step.

No

Warm up the engine, then go to Step 9.

INSPECT A/C UNIT AIR INTAKE
SYSTEM



Inspect the A/C unit air intake links, air
intake cranks, air intake rods, air intake
actuator, and wire clamp.

Yes Go to the next step.

2008 Mazda CX-9 Grand Touring

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

Microsoft

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

Page 11

© 2005 Mitchell Repair Information Company, LLC.