NO.9 FAST IDLE/RUNS ON [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5]

id0103g8801500

9

FAST IDLE/RUNS ON
DESCRIPTION
•  Engine speed continues at fast idle after warm-up.
•  Engine runs after ignition switch is turned off.
POSSIBLE CAUSE
•  Cooling system malfunction
•  PCM DTC is stored
•  Accelerator pedal stuck depressed
•  Erratic signal to PCM
―  APP sensor or related circuit malfunction
―  CPP switch or related circuit malfunction (MTX)
―  Neutral switch No.1 or related circuit malfunction (MTX)
―  Communication error between TCM and PCM (ATX)
―  A/F sensor or related circuit malfunction
―  HO2S or related circuit malfunction
―  Improper air/fuel mixture ratio control operation
•  Improper load signal input
―  Improper A/C request signal
•  Improper operation of drive-by-wire control system
•  Throttle body malfunction
•  Fuel injector malfunction
•  Spill valve control solenoid valve (built-into high pressure fuel pump) malfunction
•  Improper operation of cruise control system
•  Air leakage from intake-air system
•  Injector driver (built-into PCM) malfunction
Warning
The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:
•  Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
•  Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual. (See BEFORE SERVICE PRECAUTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See AFTER SERVICE PRECAUTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].)
Caution
•  Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

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 completely.
•  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}:
•  Perform the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING".
ECT PID value is less than 82 °C {180 °F}:
•  Perform the symptom troubleshooting "NO.18 COOLING SYSTEM CONCERNS-RUNS COLD".
2
VERIFY PCM DTC
•  Retrieve any DTCs using the M-MDS.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].)
No
Go to the next step.
3
VERIFY CURRENT INPUT SIGNAL STATUS
Caution
•  While performing this step, always operate the vehicle in a safe and lawful manner.
•  When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
•  Access the following PIDs using the M-MDS:
―  APP1
―  APP2
―  CPP (MTX)
―  CPP/PNP (MTX)
―  O2S11
―  O2S12
―  SHRTFT1
―  LONGFT1
•  Do the PIDs indicate the correct values under the trouble condition?
Yes
Go to the next step.
No
APP1, APP2 PIDs are not as specified:
•  Inspect the APP sensor.
CPP PID is not as specified: (MTX)
•  Inspect the CPP switch.
CPP/PNP PID is not as specified: (MTX)
•  Inspect the neutral switch No.1.
O2S11, SHRTFT1, LONGFT1 PIDs are not as specified:
•  Inspect the A/F sensor.
O2S12 PID is not as specified:
•  Inspect the HO2S.
Repair or replace the malfunctioning part according to the inspection results.
•  If the malfunction remains:
―  Inspect communication error between TCM and PCM. (ATX)
•  Repair or replace the malfunctioning part according to the inspection results if necessary.
―  Perform the “INTERMITTENT CONCERN TROUBLESHOOTING” procedure.
4
DETERMINE IF MALFUNCTION CAUSE IS A/C REQUEST SIGNAL OR OTHER
•  Access the AC_REQ PID using the M-MDS.
•  Monitor the AC_REQ PID while turning on and off the air conditioner with switch on the control panel.
•  Does the AC_REQ PID value change from on to off according to switch control panel?
Yes
Go to the next step.
No
If the AC_REQ PID is always ON:
•  Perform the symptom troubleshooting “NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY”.
If the AC_REQ PID is always OFF:
•  Perform the symptom troubleshooting “NO.23 A/C DOES NOT WORK SUFFICIENTLY”.
5
INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION
•  Perform the Electronic Control Throttle Operation Inspection.
•  Does the drive-by-wire control system work properly?
Yes
Visually inspect the throttle body (damage/scratching).
•  If there is any malfunction:
―  Repair or replace the malfunctioning part according to the inspection results.
•  If there is no malfunction:
―  Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
6
INSPECT FUEL INJECTOR OPERATION
•  Perform the Fuel Injector Operation Inspection.
•  Do the fuel injectors operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
7
INSPECT HIGH PRESSURE FUEL PUMP
•  Inspect the high pressure fuel pump.
•  Is there any malfunction?
Yes
Replace the high pressure fuel pump.
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].)
No
Go to the next step.
8
INSPECT CRUISE CONTROL SYSTEM
•  Inspect the operation of cruise control system.
•  Does the cruise control system work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
9
INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE
•  Inspect for leakage in intake-air system.
•  Is there any leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Injector driver malfunction.
•  Replace the PCM.
If the problem remains, overhaul the engine.
10
Verify the test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  If a 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.