Mazda CX-9 Grand Touring 2009 Manual page 1338

NO.9 FAST IDLE/RUNS ON [MZI-3.7]
NO.9 FAST IDLE/RUNS ON (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
9
DESCRIPTION
POSSIBLE CAUSE
DIAGNOSTIC PROCEDURE
NO.9 FAST IDLE/RUNS ON (MZI-3.7) DIAGNOSTIC PROCEDURE
STEP INSPECTION
Connect the M-MDS to the DLC-2.
Access ECT PID.
Start and warm up engine to normal
1
operating temperature.
Is ECT PID between 82-112°C
{180-234°F}?
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?
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
If vehicle is not repaired or additional diagnostic information is not available,
replace the PCM.
(See PCM REMOVAL/INSTALLATION [MZI-3.7] .)
FAST IDLE/RUNS ON
The engine speed continues at fast idle after warm-up.
The engine runs after the ignition switch is turned off.
CHT sensor malfunction
Air leakage from intake-air system
Throttle body malfunction
Accelerator pedal position sensor misadjustment
Cruise control system operation improperly
Improper load signal input
Improper operation of electronic throttle control system
RESULTS
Yes
No
Yes
No
Yes
ACTION
Go to the next step.
ECT PID is higher than 112°C {234°F}:
Go to symptom troubleshooting "No.17 Cooling
system concerns - Overheating".
ECT PID is less than 82°C {180°F}:
Go to symptom troubleshooting "No.18 Cooling
system concerns - Runs cold".
DTC is displayed:
Go to the appropriate DTC inspection.
(See DTC TABLE [MZI-3.7] .)
No DTC is displayed:
Go to the next step.
Go to the next step.
If the AC_REQ PID is not normal:
Inspect A/C switch, refrigerant pressure
switch, and fan switch, and related wiring
harness for vibration or intermittent
open/short circuit.