Mazda CX-9 Grand Touring 2007 Manual page 836

2007 ENGINE PERFORMANCE Symptom Troubleshooting (MZI-3.5) - CX-9
DIAGNOSTIC PROCEDURE
DIAGNOSTIC PROCEDURE
STEP INSPECTION
1 Inspect for the following:
Vacuum leakage
Proper fuel quality (such as
proper octane, contamination,
winter/summer blend)
Loose bands on intake-air system
Cracks on intake-air system parts
Intake-air system restriction
(such as air cleaner element,
fresh air duct.)
Are all items normal?
2 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?
3 Is engine overheating?
4 Inspect the ignition coil related wiring
harness condition (intermittent open or
short circuit) for all cylinders.
Are wiring harness conditions normal?
5 Inspect the spark plug conditions.
Is spark plug wet, covered with carbon
or grayish white?
6 Visually inspect the CKP sensor and
teeth of crankshaft pulley.
Are the CKP sensor and teeth of
2007 Mazda CX-9 Grand Touring
RESULTS ACTION
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
Go to the next step.
Service if necessary.
Repeat Step 1.
DTC is displayed:
Go to the appropriate DTC inspection.
(see DTC TABLE [MZI-3.5] .)
No DTC is displayed:
Go to the next step.
Go to symptom troubleshooting "No. 17
Cooling system concerns-Overheating".
(See NO.17 COOLING SYSTEM
CONCERNS-OVERHEATING
[MZI-3.5].)
Go to the next step.
Go to the next step.
Repair the wiring harnesses.
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.
Go to the next step.