Mazda CX-9 Grand Touring. Manual — part 255

6

INSPECT CMP SENSOR



Inspect the CMP sensor. (See
CRANKSHAFT POSITION
(CKP) SENSOR INSPECTION
[MZI-3.7] .)



Is there any malfunction?

Yes

malfunctioning parts.



If it is normal, replace CMP sensor. (See
CRANKSHAFT POSITION (CKP)
SENSOR REMOVAL/INSTALLATION
[MZI-3.7] .)

Then go to Step 18.

No

Go to the next step.

7

VERIFY CKP SENSOR
INSTALLATION CONDITION



Inspect for CKP sensor looseness.



Is the CKP sensor loose?

Yes

Retighten the CKP sensor, then go to Step 18.
(See CRANKSHAFT POSITION (CKP)
SENSOR REMOVAL/INSTALLATION
[MZI-3.7] .)

No

Go to the next step.

8

INSPECT IGNITION SYSTEM
OPERATION



Perform the spark test. (See
ENGINE CONTROL SYSTEM
OPERATION INSPECTION
[MZI-3.7] .)



Are the results of the spark test
normal?

Yes Go to the next step.

No

Repair or replace the malfunctioning part

according to the spark test results, then go to Step

18.

9

INSPECT MAF PID



Start the engine.



Access the MAF PID using the M-
MDS.



Verify that the MAF PID changes
quickly according to the engine speed
when the engine is raced.



Is the MAF PID response normal?

Yes Go to the next step.

No

Replace the MAF/IAT sensor, then go to Step 18.

(See INTAKE-AIR SYSTEM

REMOVAL/INSTALLATION [MZI-3.7] .)

10

INSPECT FOR EXCESSIVE AIR
SUCTION IN INTAKE AIR SYSTEM



Inspect for air leakage at the
following:



Between the MAF/IAT sensor
and the throttle body



Between the throttle body and
the dynamic chamber



Is there any malfunction?

Yes

Repair or replace the suspected part, then go to
Step 18.

No

Go to the next step.

If the fuel line pressure is too low, go to the next

2008 Mazda CX-9 Grand Touring

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

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Page 153

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11

INSPECT FUEL LINE PRESSURE



Turn the ignition switch off.



Inspect the fuel line pressure. (See
FUEL LINE PRESSURE
INSPECTION [MZI-3.7] .)



Is there any malfunction?

Yes

step. If the fuel line pressure is excessively high,
check as follows:



Fuel pump maximum pressure



Fuel return line for clogging



If all of the above are normal, replace
the pressure regulator. (See
PRESSURE REGULATOR
INSPECTION [MZI-3.7] .)

Then go to Step 18.

No

Go to Step 18.

12

INSPECT FUEL LINE FROM FUEL
PUMP TO FUEL DELIVERY PIPE



Visually inspect the fuel line for any
leakage.



Is any fuel leakage found?

Yes Replace suspected fuel line, then go to Step 18.

No

Inspect the low-pressure side fuel filter for the

following:



Foreign material or staining inside the fuel

filter

Perform the following actions as a result:



If foreign material or staining is found

inside the fuel filter (low-pressure side),

clean the fuel tank and filter.



If normal, replace the fuel pump unit. (See

FUEL PUMP UNIT

REMOVAL/INSTALLATION [MZI-

3.7] .)

Then, go to Step 18.

13

INSPECT ENGINE COMPRESSION



Inspect the engine compression. (See
COMPRESSION INSPECTION
[MZI-3.7] .)



Is it normal?

Yes Go to the next step.

No

Perform an engine overhaul for repairs, then go to

Step 18.

14

INSPECT VARIABLE VALVE
TIMING CONTROL SYSTEM
OPERATION



Inspect the variable valve timing
control system operation. (See

Yes Go to the next step.

2008 Mazda CX-9 Grand Touring

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:08:36 AM

Page 154

© 2005 Mitchell Repair Information Company, LLC.

ENGINE CONTROL SYSTEM
OPERATION INSPECTION
[MZI-3.7] .)



Does the variable timing control
system work properly?

No

Repair or replace the malfunctioning part

according to the variable valve timing control

system inspection results, then go to Step 18.

15

INSPECT OPERATION OF PURGE
SOLENOID VALVE



Inspect the purge control system
operation. (See ENGINE
CONTROL SYSTEM
OPERATION INSPECTION
[MZI-3.7] .)



Does the purge control system work
properly?

Yes Go to the next step.

No

Repair or replace the malfunctioning part

according to the purge control system inspection

results, then go to Step 18.

16

INSPECT PCV VALVE OPERATION



Turn the ignition switch off.



Remove the PCV valve and check
the valve operation. (See POSITIVE
CRANKCASE VENTILATION
(PCV) VALVE INSPECTION
[MZI-3.7] .)



Is the PCV valve operation normal?

Yes Replace the PCV valve, then go to Step 18.

No

Go to the next step.

17

INSPECT SEALING OF ENGINE
COOLANT PASSAGE

WARNING:



Never remove the cooling system
cap or loosen the radiator drain
plug while the engine is running, or
when the engine and radiator are
hot. Scalding engine coolant and
steam may shoot out and cause
serious injury. It may also damage
the engine and cooling system.



Turn off the engine and wait until it
is cool. Even then, be very careful
when removing the cap. Wrap a
thick cloth around it and slowly
turn it counterclockwise to the first
stop. Step back while the pressure
escapes



When you are sure all the pressure
is gone, press down on the cap
using the cloth, turn it, and remove
it.

Yes

Air penetrates due to poor sealing of the head
gasket or other areas between the combustion
chamber and the engine coolant passage. Repair
or replace malfunctioning parts, then go to the
next step.

2008 Mazda CX-9 Grand Touring

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:08:36 AM

Page 155

© 2005 Mitchell Repair Information Company, LLC.

DTC P0301, P0302, P0303, P0304, P0305, P0306, P0316 [MZI-3.7]

DTC P0301, P0302, P0303, P0304, P0305, P0306, P0316 (MZI-3.7) DETECTION CONDITIONS AND
POSSIBLE CAUSES



Remove the radiator cap.



Implement the procedure to bleed air
from the engine coolant, then run the
engine at idle



Are there any small bubbles which
make the engine coolant white at the
filling opening?

NOTE:



Large bubbles are normal
since they are remaining air
coming from the engine
coolant passage.

No

Go to the next step.

18

VERIFY TROUBLESHOOTING OF
DTC P0300 HAS BEEN COMPLETED



Verify that all disconnected
connectors are reconnected.



Clear the DTC from the PCM
memory using the M-MDS.



Perform the KOER SELF TEST
using the M-MDS. (See
KOEO/KOER SELF TEST [MZI-
3.7].)



Is the PENDING CODE for this
DTC present?

Yes

Replace the PCM, then go to the next step. (See
PCM REMOVAL/INSTALLATION [MZI-
3.7] .)

No

Go to the next step.

19

VERIFY AFTER REPAIR
PROCEDURE



Perform the "AFTER REPAIR
PROCEDURE". (See AFTER
REPAIR PROCEDURE [MZI-
3.7].)



Are any DTC present?

Yes

Go to the applicable DTC inspection. (See DTC
TABLE [MZI-3.7].)

No

Troubleshooting completed.

DTC P0301

P0301: Cylinder No.1 misfire detected

DTC P0302

P0302: Cylinder No.2 misfire detected

DTC P0303

P0303: Cylinder No.3 misfire detected

DTC P0304

P0304: Cylinder No.4 misfire detected

2008 Mazda CX-9 Grand Touring

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:08:36 AM

Page 156

© 2005 Mitchell Repair Information Company, LLC.