NO.9 FAST IDLE/RUNS ON [MZR 1.6]

id0103f9801500

9

FAST IDLE/RUNS ON

DESCRIPTION

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

•  The engine runs after ignition is switched off.

POSSIBLE CAUSE

•  ECT sensor malfunction

•  Continuous memory DTC is stored

•  Improper load signal input

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

―  CPP switch malfunction (MTX)

―  Neutral switch malfunction (MTX)

―  TR switch malfunction (ATX)

•  Air leakage from intake-air system

•  Improper operation of drive-by-wire control system

•  APP sensor malfunction

•  PCM malfunction

9	FAST IDLE/RUNS ON
DESCRIPTION	• The engine speed continues during at fast idle after warm-up. • The engine runs after ignition is switched off.
POSSIBLE CAUSE	• ECT sensor malfunction • Continuous memory DTC is stored • Improper load signal input ― A/C switch, refrigerant pressure sensor and fan switch malfunction ― CPP switch malfunction (MTX) ― Neutral switch malfunction (MTX) ― TR switch malfunction (ATX) • Air leakage from intake-air system • Improper operation of drive-by-wire control system • APP sensor malfunction • PCM malfunction

Diagnostic Procedure

STEP	INSPECTION	ACTION
1	Access the ECT PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) Start the engine and warm it up to normal operating temperature. Is the ECT PID value between 82—112 °C {180—234 °F}?	Yes	Go to the next step.
1		No	ECT PID is more than 112 °C {234 °F}: • Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”. (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [MZR 1.6].) 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 [MZR 1.6].)
2	Connect the M-MDS to the DLC-2. Perform the DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) Are any continuous memory DTCs present?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 1.6].)
2		No	Go to the next step.
3	Access the following PIDs using the M-MDS: (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) (See ON-BOARD DIAGNOSTIC SYSTEM PID/DATA MONITOR INSPECTION [PCM (FN4A-EL)].) • AC_REQ • CPP • CPP/PNP • TR Are all PIDs normal? (See PCM INSPECTION [MZR 1.6].)	Yes	Go to the next step.
3		No	AC_REQ: • Inspect the A/C switch, refrigerant pressure sensor and fan switch. (See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) (See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].) CPP: • Inspect the CPP switch (MTX). (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [MZR 1.6].) CPP/PNP: • Inspect the neutral switch (MTX). (See NEUTRAL SWITCH INSPECTION [MZR 1.6].) TR: • Inspect the TR switch (ATX). (See TRANSAXLE RANGE (TR) SWITCH REMOVAL/INSTALLATION [FN4A-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 the engine to higher speed?	Yes	Repair or replace the malfunctioning part according to the inspection results.
4		No	Inspect the following: • Drive-by-wire control system operation (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.6].) • APP sensor (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 1.6].) Repair or replace the malfunctioning part according to the inspection results.
5	Verify the test results. • If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 1.6].) • 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 [MZR 1.6].)