NO.9 FAST IDLE/RUNS ON [MZI-3.7]
NO.9 FAST IDLE/RUNS ON (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
DIAGNOSTIC PROCEDURE
NO.9 FAST IDLE/RUNS ON (MZI-3.7) DIAGNOSTIC PROCEDURE
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If vehicle is not repaired or additional diagnostic information is not available,
replace the PCM.
(See
PCM REMOVAL/INSTALLATION [MZI-3.7]
.)
9
FAST IDLE/RUNS ON
DESCRIPTION
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The engine speed continues at fast idle after warm-up.
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The engine runs after the ignition switch is turned off.
POSSIBLE CAUSE
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CHT sensor malfunction
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Air leakage from intake-air system
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Throttle body malfunction
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Accelerator pedal position sensor misadjustment
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Cruise control system operation improperly
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Improper load signal input
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Improper operation of electronic throttle control system
STEP
INSPECTION
RESULTS
ACTION
1
Connect the M-MDS to the DLC-2.
Access ECT PID.
Start and warm up engine to normal
operating temperature.
Is ECT PID between
82-112°C
{180-234°F}?
Yes
Go to the next step.
No
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".
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?
Yes
DTC is displayed:
Go to the appropriate DTC inspection.
(See
DTC TABLE [MZI-3.7]
.)
No
No DTC is displayed:
Go to the next step.
Yes
Go to the next step.
If the AC_REQ PID is not normal:
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Inspect A/C switch, refrigerant pressure
switch, and fan switch, and related wiring
harness for vibration or intermittent
open/short circuit.
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
Microsoft
Sunday, November 15, 2009 10:10:05 AM
Page 47
© 2005 Mitchell Repair Information Company, LLC.
