Spark Plug Condition: Outline

SPARK PLUG CONDITION (SKYACTIV-G) DESCRIPTION AND POSSIBLE CAUSE

Troubleshooting item	Spark plug condition
Description	Incorrect spark plug condition.
Possible cause	NOTE: Inspecting the spark plug conditions can determine whether a problem is related to a specific cylinder or possibly all cylinders. Wet/carbon stuck on specific plug: Spark-related malfunction Weak spark or no spark of specific cylinder Fuel adjustment-related malfunction Excessive fuel injection amount Compression pressure-related malfunction No compression or low compression pressure Spark plug malfunction Grayish white with specific plug: Fuel adjustment-related malfunction Insufficient fuel injection amount Spark plug malfunction If a spark plug on a specific cylinder is damaged or corroded: Spark plug malfunction Damage or corrosion due to pre-ignition or knocking Wet/carbon is stuck on all plugs: Spark-related malfunction Spark of all cylinders is weak Fuel adjustment-related malfunction Strong A/F rich tendency (high fuel pressure) Erratic signal to PCM ECT sensor or related wiring harness malfunction MAF sensor or related wiring harness malfunction A/F sensor or related wiring harness malfunction HO2S or related wiring harness malfunction Compression pressure-related malfunction Low compression pressure Restriction in intake/exhaust system Grayish white with all plugs: Erratic signal to PCM ECT sensor or related wiring harness malfunction MAF sensor or related wiring harness malfunction A/F sensor or related wiring harness malfunction HO2S or related wiring harness malfunction Fuel adjustment-related malfunction Strong A/F lean tendency (low fuel pressure) 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. (Refer to BEFORE SERVICE PRECAUTION [SKYACTIV-G 2.0] in service information.) 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. (Refer to QUICK RELEASE CONNECTOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0] in service information.) (Refer to AFTER SERVICE PRECAUTION [SKYACTIV-G 2.0] in service information.) 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.
System wiring diagram	Not applicable