Mazda CX-9 Grand Touring 2009 Manual page 1314

STEP INSPECTION
Inspect for the following:
Vacuum leakage
Proper fuel quality (such as proper
octane, contamination,
winter/summer blend)
Loose bands on intake-air system
1
Cracks on intake-air system parts
Intake-air system restriction (such
as air cleaner element, fresh air
duct.)
Are all items normal?
Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON
2 position (Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?
3 Is engine overheating?
Inspect the ignition coil related wiring
harness condition (intermittent open or
4
short circuit) for all cylinders.
Are wiring harness conditions normal?
Inspect the spark plug conditions.
5 Is spark plug wet, covered with carbon or
grayish white?
Visually inspect the CKP sensor and
teeth of crankshaft pulley.
6
Are the CKP sensor and teeth of
crankshaft pulley normal?
Remove and shake the PCV valve.
7
Does the PCV valve rattle?
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
RESULTS
No
No
No
No
No
No
No
Yes Go to the next step.
Service if necessary.
Repeat Step 1.
DTC is displayed:
Yes Go to the appropriate DTC inspection.
(See DTC TABLE [MZI-3.7] .)
No DTC is displayed:
Go to the next step.
Go to symptom troubleshooting "No. 17
Cooling system concerns-Overheating".
Yes (See NO.17 COOLING SYSTEM
CONCERNS-OVERHEATING [MZI-
3.7].)
Go to the next step.
Yes Go to the next step.
Repair the wiring harnesses.
Spark plug is wet or covered with carbon:
Yes 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.
Yes Go to the next step.
Replace the malfunctioning part.
Yes Go to the next step.
Replace the PCV valve.
Inspect the electronic throttle control system
ACTION