9

FAST IDLE/RUNS ON

DESCRIPTION

• Engine speed continues at fast idle after warm-up.

• Engine runs after ignition is switched 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 (MT)

• Neutral switch or related circuit malfunction (MT)

• Communication error between TCM and PCM (AT)

• ECT sensor No.1 or related circuit malfunction

• 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.

• Highly pressurized fuel may spray out if the fuel line is cut. Due to the following dangers occurring with a fuel spray, always complete the “Fuel Line Safety Procedure” to prevent the fuel from spraying. (See BEFORE SERVICE PRECAUTION [SKYACTIV-G 2.0].)

• Fuel may cause irritation if it comes in contact with skin and eyes.

• If fuel ignites and causes a fire, it may lead to serious injury or death, and damage to property and facilities.

• Fuel is highly flammable and dangerous. Fuel line spills and leakage can cause serious injury or death, and damage to equipment. Always refer to the “Quick Release Connector Removal/Installation (fuel system)” before performing the fuel hose installation, and execute the “Fuel Leakage Inspection” after installation. (See QUICK RELEASE CONNECTOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0].) (See AFTER SERVICE PRECAUTION [SKYACTIV-G 2.0].)

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.

Item (definition)

Unit/Condition

Definition

Condition/Specification (Reference)

AC_REQ

Off/On

A/C switch status received by PCM via CAN

• A/C switch on: On

• A/C switch off: Off

APP1

%

Accelerator pedal opening angle (absolute value) input from APP sensor No.1

• Accelerator pedal released: Approx. 15.29%

• Accelerator pedal fully depressed: Approx. 90.98%

V

APP sensor No.1 voltage

• Accelerator pedal released: Approx. 0.77 V

• Accelerator pedal fully depressed: Approx. 4.55 V

APP2

%

Accelerator pedal opening angle (absolute value) input from APP sensor No.2

• Accelerator pedal released: Approx. 7.84%

• Accelerator pedal fully depressed: Approx. 45.49%

V

APP sensor No.2 voltage

• Accelerator pedal released: Approx. 0.38 V

• Accelerator pedal fully depressed: Approx. 2.27 V

CPP (MT)

Off/On

Clutch pedal position

• Clutch pedal released: Off

• Clutch pedal fully depressed: On

CPP/PNP (MT)

Off/On

Shift lever position

• Neutral: On

• Other than neutral: Off

ECT

°C, °F

Engine coolant temperature input from ECT sensor No.1

• Displays ECT

V

ECT sensor No.1 voltage

Ignition switched ON (engine off)

• ECT is 92 °C {198 °F}: Approx. 0.65 V

Idle (after warm up)

• ECT is 93 °C {199 °F}: Approx. 0.64 V

Racing (Engine speed is 2,000 rpm)

• ECT is 92 °C {198 °F}: Approx. 0.66 V

Racing (Engine speed is 4,000 rpm)

• ECT is 93 °C {199 °F}: Approx. 0.64 V

FUEL_PRES

KPa , mBar , psi, in H20

Fuel pressure input from fuel pressure sensor

• Displays fuel pressure

V

Fuel pressure sensor voltage

Ignition switched ON (engine off)

• Fuel pressure is approx. 3.6 MPa {37 kgf/cm², 522 psi}: Approx. 1.01 V (ECT is 92 °C {198 °F})

Idle (after warm up)

• Fuel pressure is approx. 3.45 MPa {35.2 kgf/cm², 500 psi}: Approx. 1 V (ECT is 92 °C {198 °F})

Racing (Engine speed is 2,000 rpm)

• Fuel pressure is approx. 3.21 MPa {32.7 kgf/cm², 466 psi}: Approx. 0.96 V (ECT is 86 °C {187 °F})

Racing (Engine speed is 4,000 rpm)

• Fuel pressure is approx. 5.59 MPa {57.0 kgf/cm², 811 psi}: Approx. 1.29 V (ECT is 84 °C {183 °F})

LOAD

%

Ratio of actual amount of intake air to the maximum air charging amount (mass volume) of cylinder

• Idle (after warm up): Approx. 27.05% (ECT is 91 °C {196 °F})

• Racing (engine speed is 2,000 rpm): Approx. 16.86% (ECT is 89 °C {192 °F})

• Racing (engine speed is 4,000 rpm): Approx. 17.64% (ECT is 87 °C {189 °F})

LONGFT1

%

Fuel learning correction amount estimated based on A/F sensor signal

• Idle (after warm up): Approx. −1.56% (ECT is 91 °C {196 °F})

• Racing (engine speed is 2,000 rpm): 2.34% (ECT is 89 °C {192 °F})

• Racing (engine speed is 4,000 rpm): 2.34% (ECT is 87 °C {189 °F})

O2S11

µA

A/F sensor current

• Idle (after warm up): −59 µA (ECT is 92 °C {198 °F})

• Deceleration fuel cut (accelerator pedal released from engine speed of 4,000 rpm or more): Approx. 3.48 mA (ECT is 92 °C {198 °F})

O2S12

V

HO2S voltage

• Idle (after warm up): 0—1.0 V (ECT is 91 °C {196 °F})

• Deceleration fuel cut (accelerator pedal released from engine speed of 4,000 rpm or more): Approx. 0 V (ECT is 92 °C {198 °F})

RPM

RPM

Engine speed

• Displays engine speed

SHRTFT1

%

Fuel feedback correction amount estimated based on A/F sensor signal

• Idle (after warm up): Approx. 0% (ECT is 91 °C {196 °F})

• Racing (engine speed is 2,000 rpm): Approx. 0.78% (ECT is 89 °C {192 °F})

• Racing (engine speed is 4,000 rpm): Approx. −21.87% (ECT is 87 °C {189 °F})

TP_REL

%

Throttle valve opening angle (relative value) with value at throttle valve fully close timing as the start point

• Accelerator pedal released: Approx. 12.15%

• Accelerator pedal fully depressed: Approx. 81.96%

VSS

KPH, MPH

Vehicle speed

• Displays vehicle speed

STEP

INSPECTION

RESULTS

ACTION

1

• Access the ECT PID using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].)

• 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".

  (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [SKYACTIV-G 2.0].)

ECT PID value is less than 82 °C {180 °F}:

• Perform the symptom troubleshooting "NO.18 COOLING SYSTEM CONCERNS-RUNS COLD".

  (See NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [SKYACTIV-G 2.0].)

2

• Retrieve any DTCs using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [PCM (SKYACTIV-G 2.0)].)

No

Go to the next step.

3

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:

  (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].)

• APP1

• APP2

• CPP (MT)

• CPP/PNP (MT)

• ECT

• O2S11

• O2S12

• SHRTFT1

• LONGFT1

• Do the PIDs indicate the correct values under the trouble condition?

  (See PCM INSPECTION [SKYACTIV-G 2.0].)

Yes

Go to the next step.

No

APP1, APP2 PIDs are not as specified:

• Inspect the APP sensor.

  (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [SKYACTIV-G 2.0].)

CPP PID is not as specified: (MT)

• Inspect the CPP switch.

  (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [SKYACTIV-G 2.0].)

CPP/PNP PID is not as specified: (MT)

• Inspect the neutral switch.

  (See NEUTRAL SWITCH INSPECTION [SKYACTIV-G 2.0].)

ECT PID is not as specified:

• Inspect the ECT sensor No.1.

  (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [SKYACTIV-G 2.0].)

O2S11, SHRTFT1, LONGFT1 PIDs are not as specified:

• Inspect the A/F sensor.

  (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [SKYACTIV-G 2.0].)

O2S12 PID is not as specified:

• Inspect the HO2S.

  (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [SKYACTIV-G 2.0].)

Repair or replace the malfunctioning part according to the inspection results.

• If the malfunction remains:

• Inspect communication error between TCM and PCM. (AT)

• Repair or replace the malfunctioning part according to the inspection results if necessary.

• Perform the “INTERMITTENT CONCERN TROUBLESHOOTING” procedure.

  (See INTERMITTENT CONCERN TROUBLESHOOTING [SKYACTIV-G 2.0].)

4

• Access the AC_REQ PID using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].)

• 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”.

  (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [SKYACTIV-G 2.0].)

If the AC_REQ PID is always OFF:

• Perform the symptom troubleshooting “NO.23 A/C DOES NOT WORK SUFFICIENTLY”.

  (See NO.23 A/C DOES NOT WORK SUFFICIENTLY [SKYACTIV-G 2.0].)

5

• Will the engine run smoothly at part throttle?

Yes

Go to Step 7.

No

Go to the next step.

6

• Perform the Electronic Control Throttle Operation Inspection.

  (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.0].)

• 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.

7

• Perform the Fuel Injector Operation Inspection.

  (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.0].)

• Do the fuel injectors operate properly?

Yes

Go to the next step.

No

Repair or replace the malfunctioning part according to the inspection results.

8

• Inspect the high pressure fuel pump.

  (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

Replace the high pressure fuel pump.

(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

No

Go to the next step.

9

• 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.

10

• 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.

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

If the problem remains, overhaul the engine.

11

Verify the test results.

• If normal, return to the diagnostic index to service any additional symptoms.

  (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.0].)

• If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.

• If the vehicle is repaired, troubleshooting is completed.

• If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.