NO.9 FAST IDLE/RUNS ON

id0103f2801500

9

FAST IDLE/RUNS ON
DESCRIPTION
•  The engine speed continues at fast idle after warm-up.
•  The engine runs after the ignition switch is turned off.
POSSIBLE CAUSE
•  ECT sensor malfunction
•  Air leakage from intake-air system
•  Throttle body malfunction (stuck open)
•  APP sensor malfunction
•  Cruise control system operation improperly
•  Improper load signal input
•  Improper operation of drive-by-wire control system

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Connect the WDS or equivalent to the DLC-2.
Access the ECT PID.
Start and warm up the engine to normal operating temperature.
Is the ECT PID reading 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.)
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.)
2
Connect the WDS or equivalent to the DLC-2.
Retrieve any continuous memory DTCs for PCM, TCM, ABS HU/CU, DSC HU/CU and EPS CM.
Are there any DTCs displayed?
Yes
DTC is displayed:
Go to the applicable DTC inspection.
(See DTC TABLE.)
No
No DTC is displayed:
Go to the next step.
3
Connect the WDS or equivalent to the DLC-2.
Access AC_REQ, COLP, CPP (MT), CPP/PNP (MT) and TR (AT) PIDs.
Monitor each PID.
(See PCM INSPECTION.)
Are the PIDs normal?
Yes
Go to the next step.
No
AC_REQ PID: Inspect the A/C switch, the refrigerant pressure switch and the fan switch.
(See REFRIGERANT PRESSURE SWITCH INSPECTION.)
(See CLIMATE CONTROL UNIT INSPECTION.)
COLP PID: Inspect the refrigerant pressure switch (medium pressure).
(See REFRIGERANT PRESSURE SWITCH INSPECTION.)
CPP PID: Inspect the CPP switch (MT).
(See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION.)
CPP/PNP PID: Inspect the neutral switch (MT).
(See NEUTRAL SWITCH INSPECTION.)
TR PID: Inspect the TR switch (AT) and the communication line (PCM—TCM).
(See TRANSMISSION RANGE (TR) SWITCH INSPECTION.)
4
Is there air leakage felt or heard at the intake-air system components while racing the engine to a higher speed?
Yes
Repair or replace parts if necessary.
No
Inspect the following:
•  Drive-by-wire control system operation
•  APP sensor
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.