NO.9 FAST IDLE/RUNS ON [L5]SM2444472
NO.9 FAST IDLE/RUNS ON [L5]

id0103a8801500

9

FAST IDLE/RUNS ON

DESCRIPTION
• Engine speed continues at fast idle after warm-up.
• Engine runs after the ignition is off.
POSSIBLE CAUSE
• ECT sensor malfunction
• A/C switch malfunction
• Refrigerant pressure sensor malfunction
• Evaporator temperature sensor malfunction
• FAN switch malfunction
• Communication error between climate control unit and instrument cluster
• Communication error between instrument cluster and PCM
• TR switch malfunction
• Communication error between TCM and PCM
• Air leakage from intake air system
• Improper operation of electronic throttle control system
• APP sensor malfunction

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
Access the ECT PID using the M-MDS.
Start and warm up the engine to normal operating temperature.
Is the ECT PID value between 82—112 °C {180—234 °F}?
Yes
Go to the next step.
No
ECT PID value is higher than 112 °C {234 °F}:
• Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”. (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [L5].)
ECT PID value is less than 82 °C {180 °F}:
• Go to the symptom troubleshooting “NO.18 COOLING SYSTEM CONCERNS-RUNS COLD”. (See NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [L5].)
2
Perform the PCM DTC inspection using the M-MDS.
Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
Go to the next step.
3
Access the AC_REQ and TR PIDs using the M-MDS.
Are the PID values normal?
Yes
Go to the next step.
No
AC_REQ PID is not specified:
• Inspect the A/C switch, refrigerant pressure sensor, evaporator temperature sensor and fan switch. (See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].)
• Inspect communication error between climate control unit and instrument cluster.
• Inspect communication error between instrument cluster and PCM.
TR PID is not specified:
• Inspect the TR switch. (See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FS5A-EL].)
• Inspect communication error between TCM and PCM.
Repair or replace the malfunctioning part according to the inspection results.
4
Is there air leakage felt or heard at the intake air system components while racing the engine to higher speed?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Inspect the following:
• Electronic throttle control system operation (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L5].)
Repair or replace the malfunctioning part according to the inspection results.
5
Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [L5].)
• If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
― If the vehicle is repaired, troubleshooting is completed.
― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.