NO.9 FAST IDLE/RUNS ON [L8, LF, L5]

id010346801500

9

FAST IDLE/RUNS ON

DESCRIPTION

•  The engine speed continues at fast idle after warm-up.

•  The engine runs after the ignition is off.

POSSIBLE CAUSE

•  ECT sensor malfunction

•  Air leakage from intake air system

•  Throttle body malfunction

•  APP sensor misadjustment

•  Cruise control system operation improperly

•  Improper load signal input

•  Improper operation of electronic throttle control system

9	FAST IDLE/RUNS ON
DESCRIPTION	• The engine speed continues at fast idle after warm-up. • The engine runs after the ignition is off.
POSSIBLE CAUSE	• ECT sensor malfunction • Air leakage from intake air system • Throttle body malfunction • APP sensor misadjustment • Cruise control system operation improperly • Improper load signal input • Improper operation of electronic throttle control system

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Access ECT PID. Start and warm up the engine to normal operating temperature. Is ECT PID between 82—112°C {180—234°F}?	Yes	Go to the next step.
1		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. Switch the ignition to ON (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [L8, LF, L5].)
2		No	No DTC is displayed: Go to the next step.
3	Connect the M-MDS to the DLC-2 Access the ACCS, COLP, CPP/PNP and TR PIDs. Monitor each PID. (See PCM INSPECTION [L8, LF, L5].) Are PID values normal?	Yes	Go to the next step.
3		No	ACCS PID is not specified: Inspect the A/C switch, refrigerant pressure switch and fan switch. COLP PID is not specified: Inspect the refrigerant pressure switch (middle pressure). CPP PID is not specified: Inspect the clutch switch (MTX). CPP/PNP PID: Inspect the neutral switch (MTX). TR PID: TR switch (ATX).
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 parts if necessary.
4		No	Inspect the following: • Electronic throttle control system operation • APP sensor
5	• Verify test results. ― If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [L8, LF, L5].) ― If the malfunction remains, inspect the related Service Information and perform repair or diagnosis. • If the vehicle is repaired, troubleshooting is completed. • If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [L8, LF, L5].)