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

id0103a0801500

9

FAST IDLE/RUNS ON

DESCRIPTION

•  Engine speed continues at fast idle after warm-up.

•  Engine runs after the ignition switch is turned off.

POSSIBLE CAUSE

•  ECT sensor malfunction

•  Improper load signal input

―  A/C switch, refrigerant pressure switch and fan switch

―  PSP switch

―  CPP switch (MT)

―  Neutral switch (MT)

―  TR switch (AT)

•  Air leakage from intake-air system

•  Improper operation of electronic throttle control system

•  APP sensor malfunction

•  PCM malfunction

9	FAST IDLE/RUNS ON
DESCRIPTION	• Engine speed continues at fast idle after warm-up. • Engine runs after the ignition switch is turned off.
POSSIBLE CAUSE	• ECT sensor malfunction • Improper load signal input ― A/C switch, refrigerant pressure switch and fan switch ― PSP switch ― CPP switch (MT) ― Neutral switch (MT) ― TR switch (AT) • Air leakage from intake-air system • Improper operation of electronic throttle control system • APP sensor malfunction • PCM malfunction

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Perform the PID/DATA Monitor and Record Procedure. (See ON-BOARD DIAGNOSTIC TEST [L8, LF].) Access the ECT PID. Start and warm up engine to normal operating temperature. Is the 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 the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”. (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [L8, LF].) ECT PID 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 [L8, LF].)
2	Connect the M-MDS to the DLC-2. Perform the DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [L8, LF].) Are any DTCs present?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [L8, LF].)
2		No	Go to the next step.
3	Connect the M-MDS to the DLC-2. Perform the PID/DATA Monitor and Record Procedure and access the following PIDs: (See ON-BOARD DIAGNOSTIC TEST [L8, LF].) PCM PID: • AC_REQ • PSP • CPP (MT) • CPP/PNP (MT) TCM PID: • TR (AT) Are the PIDs normal? (See PCM INSPECTION [L8, LF].)	Yes	Go to the next step.
3		No	AC_REQ: • Inspect the A/C switch, refrigerant pressure switch and fan switch. PSP: • Inspect the PSP switch. (See POWER STEERING PRESSURE (PSP) SWITCH INSPECTION [L8, LF].) CPP (MT): • Inspect the CPP switch. (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [L8, LF].) CPP/PNP (MT): • Inspect neutral switch. (See NEUTRAL SWITCH INSPECTION [L8, LF].) TR (AT): • Inspect the TR switch. (See TRANSMISSION RANGE (TR) SWITCH INSPECTION [SJ6A-EL].) 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 engine to higher speed?	Yes	Repair or replace the malfunctioning part according to the inspection results.
4		No	Inspect the following: • Electronic throttle control system operation (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L8, LF].) • APP sensor (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [L8, LF].) Repair or replace the malfunctioning part according to the inspection results.
5	Verify test results. • If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [L8, LF].) • If malfunction remains, inspect related Service information perform repair or diagnosis. ― If vehicle repaired, troubleshooting completed. ― If vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [L8, LF].)