13

KNOCKING/PINGING-ACCELERATION/CRUISE

DESCRIPTION

• Abnormal combustion occurs under the condition such as the temperature in the combustion chamber is too high resulting in abnormal noise.

• Knocking sound occurs from the engine room during acceleration.

POSSIBLE CAUSE

• Poor fuel quality

• Fuel RON is not specified

• Excessive cleaning agents added in fuel

• Poor connection of KS, wiring harness

• The following information for calculating ignition timing is incorrect:

• KS signal

• ECT sensor No.1 signal

• IAT sensor No.2 (integrated in MAP sensor) signal

• MAF sensor signal

• Air suction in intake-air system

• MAP sensor signal

• Combustion temperature is high

• Cooling system malfunction

• Carbon accumulation

• Use of non-genuine spark plug

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)

BARO

KPa , mBar , psi, in H20

Actually measured barometric pressure input from BARO sensor built into PCM

• Displays BARO

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

IAT2

°C, °F

Intake air temperature (No.2) input from IAT sensor No.2

• Displays IAT (No.2)

V

IAT sensor No.2 voltage

• IAT2 is 65 °C {149 °F}: Approx. 1.7 V

• IAT2 is 66 °C {151 °F}: Approx. 1.65 V

MAF

g/Sec

Mass air flow input from MAF sensor

• Displays MAF

V

MAF sensor voltage

• Ignition switched ON (engine off) (MAF: 0.39 g/s {0.052 lb/min}): Approx. 0.72 V (ECT is 89 °C {192 °F})

• Idle (after warm up) (MAF: 4.29 g/s {0.567 lb/min}): Approx. 1.15 V (ECT is 88 °C {190 °F})

• Racing (engine speed is 2,000 rpm) (MAF: 4.32 g/s {0.571 lb/min}): Approx. 1.15 V (ECT is 89 °C {192 °F})

• Racing (engine speed is 4,000 rpm) (MAF: 12.71 g/s {1.681 lb/min}): Approx. 1.66 V (ECT is 89 °C {192 °F})

MAP

KPa , mBar , psi, in H20

Manifold absolute pressure input from MAP sensor

• Displays MAP

MAP_V

V

MAP sensor voltage

• Ignition switched ON (engine off) (MAP:101 kPa {1.03 kgf/cm², 14.6 psi}): Approx. 4.08 V (ECT is 89 °C {192 °F})

• Idle (after warm up) (MAP: 31 kPa {0.32 kgf/cm², 4.5 psi}): Approx. 1.25 V (ECT is 88 °C {190 °F})

• Racing (engine speed is 2,000 rpm) (MAP: 32 kPa {0.33 kgf/cm², 4.6 psi}): Approx. 1.31 V (ECT is 89 °C {192 °F})

• Racing (engine speed is 4,000 rpm) (MAP: 49 kPa {0.50 kgf/cm², 7.1 psi}): Approx. 2.03 V (ECT is 89 °C {192 °F})

STEP

INSPECTION

RESULTS

ACTION

1

• 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.

2

• Drain the remaining fuel in the fuel tank and add the specified fuel.

• Leave idling for approx. 15 min to refill the hose with fuel.

• Does the symptom disappear?

Yes

Symptom troubleshooting completed.

(If customer has used fuel additive, give them advice not to use it)

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 ECT PID using the M-MDS.

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

• Is the ECT PID value less than 116 °C {241 °F} during driving?

Yes

Go to the next step.

No

The cause of this concern could be from the cooling system overheating.

• Perform the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”.

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

4

• Remove all spark plugs.

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

• Inspect the spark plug.

  (See SPARK PLUG INSPECTION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

Replace the spark plug.

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

No

Go to the next step.

5

• Verify if there is air suction into the intake air system (such as between MAF sensor and intake valve, vacuum hose, evaporative hose, ventilation hose).

  (See VACUUM HOSE REMOVAL/INSTALLATION.)

  (See EMISSION SYSTEM LOCATION INDEX [SKYACTIV-G 2.0].)

  (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

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

No

Go to the next step.

6

• Access the following PIDs using the M-MDS:

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

• MAP

• BARO

• Measure the intake manifold vacuum when idling (no load).

  (See INTAKE MANIFOLD VACUUM INSPECTION [SKYACTIV-G 2.0].)

• Does the difference between PIDs BARO and MAP nearly match the intake manifold vacuum value?

Yes

Go to the next step.

No

Replace the MAP sensor/IAT sensor No.2.

(See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO.2 REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

7

• Inspect the MAF sensor.

  (See MASS AIR FLOW (MAF) SENSOR INSPECTION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

Replace the MAF sensor/IAT sensor No.1.

(See MASS AIR FLOW (MAF) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO.1 REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

No

Go to the next step.

8

• Inspect the IAT sensor No.2 resistance.

  (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

Replace the MAP sensor/IAT sensor No.2.

(See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO.2 REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

No

Go to the next step.

9

• Inspect the ECT sensor No.1 resistance.

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

• Is there any malfunction?

Yes

Replace the ECT sensor No.1.

(See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

No

Go to the next step.

10

• Inspect the KS.

  (See KNOCK SENSOR (KS) INSPECTION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

Replace the KS, then go to the next step.

(See KNOCK SENSOR (KS) REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

No

Remove the accumulated matter in the cylinder head using the following procedure:

• Carbon remover

• Overhauling

Go to the next step.

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.