NO.9 FAST IDLE/RUNS ON [MZR 1.3, MZR 1.5]


id0103d7801500

9

FAST IDLE/RUNS ON

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

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
INSPECT COOLING SYSTEM FOR MALFUNCTION
•  Access the ECT PID using the M-MDS.
•  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.
No
ECT PID value is higher than 112 °C {234 °F}:
•  Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”.
ECT PID value is less than 82 °C {180 °F}:
•  Go to the symptom troubleshooting “NO.18 COOLING SYSTEM CONCERNS-RUNS COLD”.
2
VERIFY PCM DTC
•  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
VERIFY CURRENT INPUT SIGNAL STATUS
―  AC_REQ
―  COLP
―  CPP (MTX)
―  CPP/PNP (MTX)
―  TR (ATX, CVT)
•  Are the PID values normal?
Yes
Go to the next step.
No
AC_REQ PID is not as specified:
COLP PID is not as specified:
CPP PID is not as specified: (MTX)
CPP/PNP PID is not as specified: (MTX)
•  Inspect the neutral switch.
TR PID is not as specified: (ATX, CVT)
Repair or replace the malfunctioning part according to the inspection results.
4
INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE
•  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:
•  Drive-by-wire control system operation
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.
•  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, replace the PCM.