Mazda CX-9 Grand Touring 2009 Manual page 1356

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
between the fuel pipe and the fuel
distributor.
Start the engine and idle it.
Measure fuel line pressure during
idle.
5 Is fuel line pressure correct during
idle?
(See FUEL LINE PRESSURE
INSPECTION [MZI-3.7] .)
Inspect for variable valve timing
control system operation.
(See ENGINE CONTROL
6 SYSTEM OPERATION
INSPECTION [MZI-3.7].)
Does the variable valve timing
control system function properly?
Remove and shake the PCV valve.
7
Does the PCV valve rattle?
Visually inspect the exhaust system
part.
8
Is there any deformed exhaust
system?
Inspect for contaminated MAF
9 sensor.
Is there any contamination?
Inspect the MAF sensor for
10 contamination.
Is there any contamination?
11 Is engine compression correct?
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
12
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
Inspect the fuel pump relay and fuel pump
If there is no malfunction, replace the fuel pump
No
REMOVAL/INSTALLATION [MZI-3.7] .)
REMOVAL/INSTALLATION [MZI-3.7] .)
Yes Go to the next step.
No Repair or replace the malfunctioning part.
Yes Go to the next step.
No
Yes Replace the suspected part.
No
Yes Go to the next step.
No
Yes Replace MAF sensor.
No
Yes Inspect the valve timing.
No
circuit.
Inspect the fuel line for clogging.
unit
(See FUEL PUMP UNIT
High:
Replace the fuel pump unit.
(See FUEL PUMP UNIT
Replace the PCV valve.
Go to the next step.
Inspect for cause.
Go to the next step.
Inspect for cause.