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Mazda CX-9 Grand Touring. Manual - part 337

VSS PID:

Inspect for open circuit of VSS and related

wiring harness intermittently.

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.

Replace the malfunctioning part.

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 fuel injector.
Spark plug is grayish white:
Inspect the fuel injector for clogging.

Install the spark plugs on original

cylinders.

Go to the next step.

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

Yes

Go to the next step.

Replace the PCV valve.

Perform the electronic throttle control
system operation inspection.
(See ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
3.7].)
Does the electronic throttle control system
function properly?

Yes

Go to the next step.

Repair or replace the malfunctioning part

according to electronic throttle system

operation inspection results.

Visually inspect deformed exhaust system
part.
Is there any deformed exhaust system part?

Yes

Replace the suspected part.

Go to the next step.

Install fuel pressure gauge between the fuel
pipe and 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 with ignition
switch to ON position?
(See FUEL LINE PRESSURE
INSPECTION [MZI-3.7] .)

Yes

Go to the next step.

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 for fuel leakage at fuel
injector O-ring and fuel line.
Service if necessary.
Is fuel line pressure held after ignition

Yes

Go to the next step.

Inspect the fuel injector.

If the fuel injector is normal, replace the

fuel pump unit.

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 54

switch is turned off?
(See FUEL LINE PRESSURE
INSPECTION [MZI-3.7] .)

(See FUEL PUMP UNIT

REMOVAL/INSTALLATION [MZI-

3.7] .)

Connect a pressure gauge to A/C low and
high pressure side lines.Turn the A/C on
and measure low side and high side
pressure.Are pressures within
specifications?(See REFRIGERANT
PRESSURE CHECK .)

NOTE:



The following test is for engine
stall with the A/C on. If other
symptom exists, go to the next
step.

Yes

Go to the next step.

If the A/C is always on, go to symptom

troubleshooting "No.24 A/C is always on

or A/C compressor runs continuously".

(See NO.24 A/C IS ALWAYS ON OR

A/C COMPRESSOR RUNS

CONTINUOUSLY [MZI-3.7].)

For other symptoms, inspect the

following:



Refrigerant charging amount



Condenser fan operation

Inspect cruise control system.Is cruise
control system normal?

NOTE:



The following test should be
performed for symptom with
cruise control ON. If other
symptoms exist, go to the next
step.

Yes

Go to the next step.

Repair or replace the malfunctioning part.

Inspect the front HO2S.
(See FRONT HEATED OXYGEN
SENSOR (HO2S) INSPECTION [MZI-
3.7] .)
Is the front HO2S normal?

Yes

Go to the next step.

Replace the front HO2S.

(See REAR HEATED OXYGEN

SENSOR (HO2S)

REMOVAL/INSTALLATION [MZI-

3.7] .)

Inspect the evaporative purge hose between
the fuel tank and the purge valve.
Does fuel flow into evaporative purge
hose?

Yes

Inspect the check valve (two-way).
(See FUEL TANK INSPECTION [MZI-
3.7] .)

Go to the next step.

Disconnect the vacuum hose between the
purge solenoid valve and the intake
manifold from the purge solenoid valve
side.
Plug opening end of vacuum hose.
Drive the vehicle.
Does the engine condition improve?

Yes

Go to the next step.
Inspect if the purge solenoid valve is stuck
open mechanically.
Inspect the evaporative emission control
system.

Go to the next step.

Visually inspect the CMP sensor and
projections of camshaft pulley.
Are CMP sensor and projections of
camshaft pulley normal?

Yes

Go to the next step.

Replace the malfunctioning part.

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 55

NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [MZI-3.7]

NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE (MZI-3.7) DETECTION CONDITIONS
AND POSSIBLE CAUSES

Is the engine compression correct?

Yes

Inspect the following:



Valve timing



Internal transaxle part



Engine mounts



Check valve (two-way)

Inspect for cause.



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] .)

LACK/LOSS OF POWER-ACCELERATION/CRUISE

DESCRIPTION Performance is poor under load (such as power down when climbing hills).



Improper A/C system operation



Erratic signal or no signal from CMP sensor



Air leakage from intake-air system parts



Restriction in intake-air system



Intake air temperature too hot



Improper operation of electronic throttle control system



Purge control solenoid malfunction



Brake dragging



Erratic signal from CKP sensor



Low engine compression



Vacuum leakage



Poor fuel quality



Erratic signal to ignition coil



Engine overheating

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 56

DIAGNOSTIC PROCEDURE

POSSIBLE

CAUSE



Throttle body malfunction



Spark plug malfunction



PCV valve malfunction



Improper valve timing due to jumping out of timing chain



Improper variable valve timing control operation



Restriction in exhaust system



Intermittent open or short in fuel pump related circuit



Inadequate fuel pressure



Fuel pump mechanical malfunction



Fuel line restriction or clogging



Fuel leakage from fuel injector



Fuel injector clogging



Erratic signal from accelerator pedal position sensor



Erratic signal from TP sensor



Intermittent open or short circuit in MAF sensor, Accelerator pedal position
sensor, TP sensor, IAT sensor and VSS



ATX malfunction

WARNING:

The following troubleshooting flow chart contains the fuel system diagnosis
and repair procedures. Read the following warnings before servicing the fuel
system:



Fuel vapor is hazardous. It can easily ignite, causing serious injury
and damage. Always keep sparks and flames away from fuel.



Fuel line spills and leakage are dangerous. Fuel can ignite and cause
serious injuries or death and damage. Fuel can also irritate skin and
eyes. To prevent this, always complete "BEFORE SERVICE
PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this
manual.

(See BEFORE SERVICE PRECAUTION [MZI-3.7] .)

(See AFTER SERVICE PRECAUTION [MZI-3.7] .)

CAUTION:



Disconnecting/connecting quick release connector without cleaning it
may cause damage to fuel pipe and quick release connector. Always
clean quick release connector joint area before
disconnecting/connecting, and make sure that it is free of foreign
material.

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 57

Content .. 335 336 337 338 ..