Mazda CX-9 Grand Touring. Manual — part 333



PCM terminal 1AD-APP sensor

terminal G



PCM terminal 1AG-APP sensor

terminal H

12

Connect the M-MDS to the DLC-2.
Access the TP1, TP2 PID. Crank the
engine with accelerator pedal released.
Are the TP1, TP2 PID indicates the
closed throttle position?

Yes

Go to the next step.

No

Inspect for the following:



TP sensor



Wiring harnesses and connectors for

following:



PCM terminal 2BO-TP sensor

terminal A



PCM terminal 2BR-TP sensor

terminal B



PCM terminal 2AD-TP sensor

terminal C



PCM terminal 2D-TP sensor

terminal D



PCM terminal 2AH-TP sensor

terminal E



PCM terminal 2Z-TP sensor

terminal F

13

Does the engine start with the throttle
valve closed?

Yes

Go to Step 28.

No

Go to the next step.

14

Will the engine start and run smoothly at
part throttle?

Yes

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

No

Go to the next step.

15

Connect the M-MDS to the DLC-2.
Access RPM PID.
Is RPM PID indicating the engine speed
when cranking the engine?

Yes

Go to the next step.

No

Inspect for the following:



Open or short circuit in CKP sensor



Open or short circuit in wiring harness

between CKP sensor terminal A and

PCM terminal 2P



Open or short circuit in wiring harness

between CKP sensor terminal B and

PCM terminal 2T



Open or short circuit in CKP sensor

wiring harnesses

2008 Mazda CX-9 Grand Touring

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:10:05 AM

Page 38

© 2005 Mitchell Repair Information Company, LLC.

If CKP sensor and wiring harness are normal,

go to the next step.

16

Visually inspect the CKP sensor and
teeth of crankshaft pulley.
Are CKP sensor and teeth of crankshaft
pulley normal?

Yes

Go to the next step.

No

Replace the malfunctioning part.

17

Inspect the ignition coil related wiring
harness condition (intermittent open or
short circuit) for all cylinders. Are
wiring harness conditions normal?

Yes

Go to the next step.

No

Repair the wiring harnesses.

18

Perform the spark test.
(See ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
3.7].)
Is strong blue spark visible at each
cylinder?

Yes

Go to the next step.

No

Repair or replace the malfunctioning part

according to spark test result.

19

Inspect the spark plug conditions.
Is spark plug wet, covered with carbon
or grayish white?

Yes

Spark plug is wet or covered with carbon:
Inspect for fuel leakage from injector.
Spark plug is grayish white:
Inspect the fuel injector for clogging.

No

Install the spark plugs on original cylinders.

Go to the next step.

20

Remove and shake the PCV valve.
Does the PCV valve rattle?

Yes

Go to the next step.

No

Replace the PCV valve.

21

visually inspect the exhaust system part.
Is there any deformed exhaust system
part?

Yes

Replace the suspected part.

No

Go to the next step.

22

Install the fuel pressure gauge between
the fuel pipe and the fuel distributor.
Short check connector terminal F/P to
body GND using a jumper wiring.
Turn the ignition switch to the ON
position.
Is fuel line pressure correct when
ignition switch is turned on/off five
times?
(See FUEL LINE PRESSURE
INSPECTION [MZI-3.7] .)

Yes

Go to the next step.

No

Zero or low:

Inspect the fuel pump relay and fuel pump

circuit.

Inspect the fuel line for clogging.

If there is no malfunction, replace the fuel

pump unit.

(See FUEL PUMP UNIT

REMOVAL/INSTALLATION [MZI-

3.7] .)
High:

Replace the fuel pump unit.

(See FUEL PUMP UNIT

REMOVAL/INSTALLATION [MZI-

3.7] .)

Visually inspect the fuel injector O-ring
and fuel line for fuel leakage.

Yes

Go to the next step.

Inspect the fuel injector.

2008 Mazda CX-9 Grand Touring

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:10:05 AM

Page 39

© 2005 Mitchell Repair Information Company, LLC.

NO.7 SLOW RETURN TO IDLE [MZI-3.7]

NO.7 SLOW RETURN TO IDLE (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES

23

Service if necessary.
Is the fuel line pressure held after the
ignition switch is turned off?
(See FUEL LINE PRESSURE
INSPECTION [MZI-3.7] .)

No

If the fuel injector is normal, replace the fuel

pump unit.

(See FUEL PUMP UNIT

REMOVAL/INSTALLATION [MZI-

3.7] .)

24

Disconnect the vacuum hose between
the purge solenoid valve and the intake
manifold from purge solenoid valve
side.
Plug opening end of vacuum hose.
Start the engine.
Is starting condition improved?

Yes

Inspect if the purge solenoid valve is stuck
open mechanically.
Inspect the evaporative emission control
system.

No

Go to the next step.

25

Is air leakage felt or heard at intake-air
system components while racing engine
to higher speed?

Yes

Repair or replace the malfunctioning part.

No

Go to the next step.

26

Inspect the variable valve timing control
system operation.
(See ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
3.7].)
Does variable valve timing control
function properly?

Yes

Go to the next step.

No

Repair or replace the malfunctioning part.

27

Is the engine compression correct?

Yes

Inspect the valve timing.

No

Inspect for causes.

28



Verify test results.



If normal, return to diagnostic index to service any additional symptoms.

(See SYMPTOM DIAGNOSTIC INDEX [MZI-3.7].)



If malfunction remains, inspect related Service Bulletins and/or On-line Repair
Information and perform repair or diagnosis.



If vehicle is repaired, troubleshooting completed.



If vehicle is not repaired or additional diagnostic information is not available,
replace the PCM.

(See PCM REMOVAL/INSTALLATION [MZI-3.7] .)

7

SLOW RETURN TO IDLE

DESCRIPTION

Engine takes more time than normal to return to idle speed.



CHT sensor malfunction

2008 Mazda CX-9 Grand Touring

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:10:05 AM

Page 40

© 2005 Mitchell Repair Information Company, LLC.

DIAGNOSTIC PROCEDURE

NO.7 SLOW RETURN TO IDLE (MZI-3.7) DIAGNOSTIC PROCEDURE

POSSIBLE CAUSE



Thermostat is stuck open.



Throttle body malfunction



Air leakage from intake-air system

STEP

INSPECTION

RESULTS

ACTION

1

Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON
position (Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?

Yes

DTC is displayed:
Go to the appropriate DTC inspection.
(See DTC TABLE [MZI-3.7] .)

No

No DTC is displayed:

Go to the next step.

2

Remove thermostat and inspect operation.
(See THERMOSTAT
REMOVAL/INSTALLATION [MZI-
3.7] .)
(See THERMOSTAT INSPECTION
[MZI-3.7] .)
Is thermostat normal?

Yes

ECT and thermostat are normal.
Go to the next step.

No

Access ECT PID on the M-MDS.

Inspect for both ECT PID and temperature

gauge on instrument cluster readings.

If temperature gauge on instrument cluster

indicates normal range but ECT PID is not

same as temperature gauge reading, inspect

CHT sensor.

If temperature gauge on instrument cluster

indicates cold range but ECT PID is normal,

inspect temperature gauge and heat gauge

unit.

3

Is throttle body free of contamination?

Yes

Inspect for air leakage from the intake-air
system components while racing the engine
to higher speed.

No

Clean or replace throttle body.

4



Verify test results.



If normal, return to diagnostic index to service any additional symptoms.

(See SYMPTOM DIAGNOSTIC INDEX [MZI-3.7].)



If malfunction remains, inspect related Service Bulletins and/or On-line Repair
Information and perform repair or diagnosis.



If vehicle is repaired, troubleshooting completed.



If vehicle is not repaired or additional diagnostic information is not available,
replace the PCM.

(See PCM REMOVAL/INSTALLATION [MZI-3.7] .)

2008 Mazda CX-9 Grand Touring

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:10:05 AM

Page 41

© 2005 Mitchell Repair Information Company, LLC.