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

id0103a0801500

9 | FAST IDLE/RUNS ON
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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
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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.
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].)
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.
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.
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].)