Mazda CX-9 Grand Touring 2007 Manual page 855

2007 ENGINE PERFORMANCE Symptom Troubleshooting (MZI-3.5) - CX-9
2 Remove thermostat and inspect operation.
(see THERMOSTAT
REMOVAL/INSTALLATION [MZI-
3.5] .)
(see THERMOSTAT INSPECTION
[MZI-3.5] .)
Is thermostat normal?
3 Is throttle body free of contamination?
4
Verify test results.
If normal, return to diagnostic index to service any additional symptoms.
(See ENGINE SYMPTOM TROUBLESHOOTING [MZI-3.5].)
If malfunction remains, inspect related Service Bulletins and/or On-line Repair
Information and perform repair or diagnosis.
NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [MZI-3.5]
DESCRIPTION AND POSSIBLE CAUSES
8 ENGINE RUNS ROUGH/ROLLING IDLE
DESCRIPTION
2007 Mazda CX-9 Grand Touring
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-3.5] .)
Engine speed fluctuates between specified idle speed and lower speed and
engine shakes excessively.
Idle speed is too slow and engine shakes excessively.
Air leakage from intake-air system parts
A/C system operation is improper
Erratic signal to ignition coil
Spark plug malfunction
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.
Yes Inspect for air leakage from the
intake-air system components while
racing the engine to higher speed.
No Clean or replace throttle body.