Mazda CX-9 Grand Touring. Manual - part 443

6*

INSPECT TO SEE WHETHER 
MALFUNCTION IS IN WIRING HARNESS 
(BETWEEN REFRIGERANT PRESSURE 
SWITCH AND PCM) OR PCM  



Test voltage at A/C signal terminal of PCM.  



Is voltage approx. 12 V?  

Yes

Repair wiring harness between PCM and 
refrigerant pressure switch, then go to 
Step 16.

No

Inspect PCM, then go to Step 16.

7

INSPECT TO SEE WHETHER 
MALFUNCTION IS IN REFRIGERANT 
PRESSURE SWITCH, REFRIGERANT 
AMOUNT, OR ELSEWHERE  



Does cool air blow out when terminals B and 
C of refrigerant pressure switch connector are 
shorted?  

Yes Go to the next step.

No

Go to Step 9.

8

INSPECT TO SEE WHETHER 
MALFUNCTION IS IN REFRIGERANT 
PRESSURE SWITCH OR REFRIGERANT 
AMOUNT  



Inspect refrigerant pressure switch.  



Is it okay?  

Yes

If refrigerant amount is empty, replace 
condenser, vacuum refrigerant line more 
than 30 min by vacuum pump, and add 
refrigerant to specified level, then go to 
Step 16.

No

Replace refrigerant pressure switch, then 

go to Step 16.

9

INSPECT TO SEE WHETHER 
MALFUNCTION (SHORT CIRCUIT) IS IN 
A/C CONTROL SIGNAL CIRCUIT 
(BETWEEN A/C RELAY AND PCM) OR 
ELSEWHERE  



Does cool air blow out when terminal A of 
A/C relay connector (A/C control signal) is 
grounded?  

Yes Release short, then go to the next step.

No

Go to Step 11.

10*

INSPECT TO SEE WHETHER 
MALFUNCTION (OPEN OR SHORT 
CIRCUIT) IS IN PCM OR WIRING HARNESS 
(BETWEEN A/C RELAY AND PCM)  



Test voltage at the A/C relay control signal 
terminal of PCM.  



Is voltage approx. 12 V?  

Yes Inspect PCM, then go to Step 16.

No

Repair wiring harness between A/C relay 

and PCM, then go to Step 16.

11*

INSPECT TO SEE WHETHER 
MALFUNCTION IS IN MAGNETIC CLUTCH 
OR ELSEWHERE  



Test voltage at the following terminal of 
magnetic clutch thermal protector. 

Yes

Inspect magnetic clutch, then go to Step 
16.

 

2008 Mazda CX-9 Grand Touring 

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

  

Microsoft 

 

Sunday, November 15, 2009 10:14:51 AM

Page 28 

© 2005 Mitchell Repair Information Company, LLC. 

NO.10 NOISE WHILE OPERATING A/C SYSTEM. 

NO.10 NOISE WHILE OPERATING A/C SYSTEM DESCRIPTION AND POSSIBLE CAUSE 



Terminal B (magnetic clutch operation 
signal)  



Is voltage approx. 12 V?  

No

Go to the next step.

12

INSPECT FUSE  



Are A/C relay power supply fuses okay?  

Yes Go to the next step.

No

Replace fuse, then go to Step 16. If fuse 

burns out immediately, go to the next 

step.

13

INSPECT WIRING HARNESS BETWEEN 
FUSE BLOCK AND A/C RELAY FOR LACK 
OF CONTINUITY  



Test voltages at following terminals of A/C 
relay. 



Terminal E (A/C relay control signal)  



Terminal C (A/C control signal)  



Are voltages approx. 12 V?  

Yes Go to the next step.

No

Repair wiring harness between fuse block 

and A/C relay, then go to Step 16.

14

INSPECT TO SEE WHETHER 
MALFUNCTION IS IN A/C RELAY OR 
WIRING HARNESS (BETWEEN A/C RELAY 
AND MAGNETIC CLUTCH) AND 
EVAPORATOR TEMPERATURE SENSOR  



Test voltage at the following terminal of A/C 
relay. 



Terminal D (magnetic clutch operation 
signal)  



Is voltage approx. 12 V?  

Yes

Inspect wiring harness between A/C relay 
and magnetic clutch. 



If above wiring harness is OK, go 
to the next step.  



If above wiring harness 
malfunctions, repair wiring harness, 
then go to Step 16.  

No

Replace A/C relay, then go to Step 16.

15

INSPECT EVAPORATOR TEMPERATURE 
SENSOR  



Inspect evaporator temperature sensor.  



Is it okay?  

Yes Go to the next step.

No

Replace evaporator temperature sensor, 

then go to the next step.

16

VERIFY REPAIR  



Does cool air blow out from front/rear vents? 
(Are the results of refrigerant system 
performance test okay?)  

Yes

Troubleshooting completed. Explain 
repairs to customer.

No

Recheck malfunction symptoms, then 

repeat from Step 1 if malfunction recurs.

10

Noise while operating A/C system.



Problem with A/C basic system installation  

 

2008 Mazda CX-9 Grand Touring 

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

  

Microsoft 

 

Sunday, November 15, 2009 10:14:51 AM

Page 29 

© 2005 Mitchell Repair Information Company, LLC. 

DIAGNOSTIC PROCEDURE 

NO.10 NOISE WHILE OPERATING A/C SYSTEM DIAGNOSTIC PROCEDURE 

DESCRIPTION 



Noise from magnetic clutch, A/C compressor, hose or refrigerant line.  

POSSIBLE CAUSE 



Magnetic clutch operation noise  



A/C compressor vane noise  



A/C compressor slippage noise  



Hose or refrigerant line interference noise  

STEP

INSPECTION

ACTION

1

CHECK A/C COMPRESSOR VANE 
NOISE  



Is there a jingling, popping, beeping, 
or buzzing sound (A/C compressor 
vane noise)?  

Yes Go to Step 5.

No

Go to the next step.

2

INSPECT A/C COMPRESSOR 
SLIPPAGE NOISE  



Is there a squeaking or whirling 
sound (A/C compressor slippage 
noise)?  

Yes Go to Step 14.

No

Go to the next step.

3

INSPECT A/C COMPRESSOR 
INTERFERENCE NOISE  



Is there a rattling or vibrating sound 
(interference noise)?  

Yes Go to Step 18.

No

Go to the next step.

4

INSPECT MAGNETIC CLUTCH 
OPERATION NOISE  



Is there a clicking sound (magnetic 
clutch operation noise)?  

Yes

Adjust clearance between pressure plate of 
magnetic clutch and A/C compressor pulley, then 
go to Step 19. 
(See MAGNETIC CLUTCH 
ADJUSTMENT .)

No

Condition is normal. (Recheck malfunction 

symptoms.)

5

INSPECT A/C COMPRESSOR NOISE 
TIME  



Is noise heard continuously for more 
than 3 s after A/C compressor comes 
on?  

Yes Go to the next step.

No

Condition is normal. (Noise occurs for 2-3 s 

immediately after A/C compressor turns on.)

INSPECT IDLE SPEED  



Inspect idle speed. 

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 10:14:51 AM

Page 30 

© 2005 Mitchell Repair Information Company, LLC. 

6

(See ENGINE TUNE-UP [MZI-
3.7] .) 



Is it okay?  

No

Follow the repair instruction described in section 

01, then go to Step 19.

7

INSPECT REFRIGERANT AMOUNT 



Inspect refrigerant amount.  



Is it okay?  

Yes Go to Step 10.

No

Go to the next step.

8

INSPECT REFRIGERANT LINES  



Inspect refrigerant lines. 



Is piping free of damage and 
cracks?  



Are piping connections free of 
oil grime? (Visual inspection)  



Are piping connections free of 
gas leakage?  



Are piping installation points 
on condenser free of gas 
leakage?  



Are piping installation points 
on receiver/drier free of gas 
leakage?  



Are piping installation points 
on A/C compressor free of gas 
leakage?  



Are piping installation points 
on A/C unit free of gas leakage 



Perform gas leak inspection 
using gas leak tester.  



Are above items okay?  

Yes Go to the next step.

No

If piping or A/C component(s) is damaged or 

cracked, replace then go to Step 19. 

If there is gas leakage, repair or replace 

connection and replace condenser

(1)

, then go to 

Step 19.

9

INSPECT EVAPORATOR PIPING 
CONNECTIONS IN A/C UNIT FOR 
GAS LEAKAGE  



Are piping connections for 
evaporator in A/C unit free of gas 
leakage?  

Yes

Adjust refrigerant amount to specified level, then 
go to Step 19.

No

If piping is damaged or cracked, replace then go 

to Step 19. If there is gas leakage, repair or 

replace connection and replace condenser

(1)

, then 

go to Step 19.

10

CHECK TO SEE WHETHER 
MALFUNCTION IS IN 
COMPRESSOR OIL OR 
ELSEWHERE  



Add 20 ml {20 cc, 0.8 fl oz} of 

Yes Go to the next step.

No

Troubleshooting completed. 

 

2008 Mazda CX-9 Grand Touring 

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

  

Microsoft 

 

Sunday, November 15, 2009 10:14:51 AM

Page 31 

© 2005 Mitchell Repair Information Company, LLC.