Diagnostic Procedure

WARNING: This page is about a different variant/trim than selected.

SPARK PLUG CONDITION (PYUL) DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	VERIFY SPARK PLUG CONDITION Remove all spark plugs. (Refer to [SPARK PLUG REMOVAL/INSTALLATION ] in Service Information). Inspect the spark plug. (Refer to [SPARK PLUG INSPECTION ] in Service Information). Is there any malfunction?	Yes	Specific plug is wet or covered with carbon: Go to the next step. Specific plug looks grayish white: Go to Step 7. All plugs are wet or covered with carbon: Go to Step 9. All plugs look grayish white: Go to Step 15.
1		No	Complete the symptom troubleshooting.
2	DETERMINE IF MALFUNCTION CAUSE IS ENGINE OIL LOSS OR OTHER Are the spark plugs wet/covered with carbon from the engine oil?	Yes	Inspect all areas related to oil, working up and down. If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1.
2		No	Go to the next step.
3	VERIFY SPARK PLUG FOR MALFUNCTION Inspect the spark plugs for the following: (Refer to [SPARK PLUG INSPECTION ] in Service Information). Air gap Cracked insulator Worn electrode Heat range Is there any malfunction?	Yes	Replace the spark plug and perform the repair completion verification 1. (Refer to [SPARK PLUG REMOVAL/INSTALLATION ] in Service Information).
3		No	Go to the next step.
4	INSPECT ENGINE COMPRESSION Inspect the compression pressure at the suspected cylinder. (Refer to [COMPRESSION INSPECTION ] in Service Information). Are compression pressures within specification?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification 1.
5	INSPECT IGNITION SYSTEM OPERATION Reinstall all spark plugs (Refer to [SPARK PLUG REMOVAL/INSTALLATION ] in Service Information). Perform the Spark Test at the suspected cylinder. (Refer to [SPARK INSPECTION ] in Service Information). Is a strong blue spark visible (compare with normal cylinder)?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning location and perform the repair completion verification 1.
6	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (Refer to [FUEL LINE PRESSURE INSPECTION ] in Service Information). Is the low side fuel pressure within specification? Specification: 475-555 kPa {4.85-5.65 kgf/cm² , 68.9-80.4 psi}	Yes	Inspect the fuel injector for the following: Injection volume Fuel leakage Open or short circuit in injector (Refer to [FUEL INJECTOR INSPECTION ] in Service Information). If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1.
6		No	Zero or low: Inspect the fuel pump relay and the fuel pump circuit. (Refer to [RELAY INSPECTION ] in Service Information). Inspect the fuel line for restriction. If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1. If there is no malfunction: Replace the fuel pump unit and perform the repair completion verification 1. (Pressure regulator or fuel pump malfunction) (Refer to [FUEL PUMP UNIT REMOVAL/INSTALLATION ] in Service Information). High: Replace the fuel pump unit and perform the repair completion verification 1. (Pressure regulator malfunction) (Refer to [FUEL PUMP UNIT REMOVAL/INSTALLATION ] in Service Information).
7	VERIFY SPARK PLUG FOR MALFUNCTION Inspect the spark plug for the following: Air gap Heat range Is there any malfunction?	Yes	Replace the spark plug and perform the repair completion verification 1. (Refer to [SPARK PLUG REMOVAL/INSTALLATION ] in Service Information).
7		No	Go to the next step.
8	INSPECT FUEL INJECTOR OPERATION Perform [Fuel Injector Operation Inspection]. (Refer to [FUEL INJECTOR INSPECTION ] in Service Information). Do the fuel injectors operate properly?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning location and perform the repair completion verification 1.
9	VERIFY AIR CLEANER ELEMENT FOR MALFUNCTION Is the air cleaner element clean? (Refer to [AIR CLEANER ELEMENT INSPECTION ] in Service Information).	Yes	Go to the next step.
9		No	Repair or replace the malfunctioning location and perform the repair completion verification 1. (Refer to [AIR CLEANER ELEMENT REMOVAL/INSTALLATION ] in Service Information).
10	VERIFY CURRENT INPUT SIGNAL STATUS Access the following PIDs using the M-MDS: (See PID/DATA MONITOR INSPECTION .) PCM: ECT ECT_VOLT MAF A/F_SEN_CUR (When engine can be started) HO2S_OUT_VOLT (When engine can be started) Are the PIDs normal? (See PID/DATA MONITOR TABLE [PCM (PYUL)] .)	Yes	Go to the next step.
10		No	ECT, ECT_VOLT PIDs are not as specified: Inspect for an intermittent open circuit of the ECT sensor No. 1 and the related wiring harness. Inspect the ECT sensor. (Refer to [ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION ] in Service Information). MAF PID is not as specified: Inspect for an intermittent open circuit of the MAF sensor and the related wiring harness. Inspect the MAF sensor. (Refer to [MASS AIR FLOW (MAF) SENSOR INSPECTION ] in Service Information). A/F_SEN_CUR PID is not as specified: Inspect for an intermittent open circuit of the A/F sensor and the related wiring harness. Inspect the A/F sensor. (Refer to [AIR FUEL RATIO (A/F) SENSOR INSPECTION ] in Service Information). HO2S_OUT_VOLT PID is not as specified: Inspect for an intermittent open circuit of the HO2S and the related wiring harness. Inspect the HO2S. (Refer to [HEATED OXYGEN SENSOR (HO2S) INSPECTION ] in Service Information). Repair or replace the malfunctioning location and perform the repair completion verification 1.
11	INSPECT PURGE CONTROL SYSTEM OPERATION Perform [Purge Control System Inspection] when the engine can be started. (Refer to [PURGE SOLENOID VALVE INSPECTION ] in Service Information). Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
11		No	Go to the next step.
12	INSPECT IGNITION SYSTEM OPERATION Reinstall all spark plugs. (Refer to [SPARK PLUG REMOVAL/INSTALLATION ] in Service Information). Perform the Spark Test. (Refer to [SPARK INSPECTION ] in Service Information). Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
12		No	Repair or replace the malfunctioning location and perform the repair completion verification 1.
13	INSPECT ENGINE COMPRESSION Measure the compression pressure for each cylinder. (Refer to [COMPRESSION INSPECTION ] in Service Information). Are compression pressures within specification?	Yes	Go to the next step.
13		No	Repair or replace the malfunctioning location and perform the repair completion verification 1.
14	INSPECT ENGINE COMPRESSION Inspect the fuel line pressure. (Refer to [FUEL LINE PRESSURE INSPECTION ] in Service Information). Is the low side fuel pressure within specification? Specification: 475-555 kPa {4.85-5.65 kgf/cm² , 68.9-80.4 psi}	Yes	Visually inspect for deformed exhaust system parts. If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1.
14		No	Zero or low: Inspect the fuel pump relay and the fuel pump circuit. (Refer to [RELAY INSPECTION ] in Service Information). Inspect the fuel line for restriction. If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1. If there is no malfunction: Replace the fuel pump unit and perform the repair completion verification 1. (Pressure regulator or fuel pump malfunction) (Refer to [FUEL PUMP UNIT REMOVAL/INSTALLATION ] in Service Information). High: Replace the fuel pump unit and perform the repair completion verification 1. (Pressure regulator malfunction) (Refer to [FUEL PUMP UNIT REMOVAL/INSTALLATION ] in Service Information).
15	VERIFY CURRENT INPUT SIGNAL STATUS Access the following PIDs using the M-MDS: (See PID/DATA MONITOR INSPECTION .) PCM: ECT ECT_VOLT MAF A/F_SEN_CUR (When engine can be started) HO2S_OUT_VOLT (When engine can be started) Are the PIDs normal? (See PID/DATA MONITOR TABLE [PCM (PYUL)] .)	Yes	Go to the next step.
15		No	ECT, ECT_VOLT PIDs are not as specified: Inspect for an intermittent open circuit of the ECT sensor No. 1 and the related wiring harness. Inspect the ECT sensor. (Refer to [ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION ] in Service Information). MAF PID is not as specified: Inspect for an intermittent open circuit of the MAF sensor and the related wiring harness. Inspect the MAF sensor. (Refer to [MASS AIR FLOW (MAF) SENSOR INSPECTION ] in Service Information). A/F_SEN_CUR PID is not as specified: Inspect for an intermittent open circuit of the A/F sensor and the related wiring harness. Inspect the A/F sensor. (Refer to [AIR FUEL RATIO (A/F) SENSOR INSPECTION ] in Service Information). HO2S_OUT_VOLT PID is not as specified: Inspect for an intermittent open circuit of the HO2S and the related wiring harness. Inspect the HO2S. (Refer to [HEATED OXYGEN SENSOR (HO2S) INSPECTION ] in Service Information). Repair or replace the malfunctioning location and perform the repair completion verification 1.
16	INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE If the engine cannot be started: Inspect for leakage in intake-air system. If the engine can be started: Perform [Intake Manifold Vacuum Inspection]. (Refer to [INTAKE MANIFOLD VACUUM INSPECTION ] in Service Information). Is there any leakage?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
16		No	Go to the next step.
17	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (Refer to [FUEL LINE PRESSURE INSPECTION ] in Service Information). Is the low side fuel pressure within specification? Specification: 475-555 kPa {4.85-5.65 kgf/cm² , 68.9-80.4 psi}	Yes	Inspect the PCM ground condition. If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1.
17		No	Zero or low: Inspect the fuel pump relay and the fuel pump circuit. (Refer to [RELAY INSPECTION ] in Service Information). Inspect the fuel line for restriction. If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1. If there is no malfunction: Replace the fuel pump unit and perform the repair completion verification 1. (Pressure regulator or fuel pump malfunction) (Refer to [FUEL PUMP UNIT REMOVAL/INSTALLATION ] in Service Information). High: Replace the fuel pump unit and perform the repair completion verification 1. (Pressure regulator malfunction) (Refer to [FUEL PUMP UNIT REMOVAL/INSTALLATION ] in Service Information).
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED Install/connect the part removed/disconnected during the troubleshooting procedure. Has the malfunction symptom been eliminated?	Yes	Complete the symptom troubleshooting. (Explain contents of repair to customer)
Repair completion verification 1		No	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See MALFUNCTION DIAGNOSIS FLOW [CONTROLLER AREA NETWORK (CAN)] .) If the CAN communication is normal, perform the diagnosis from Step 1. If the malfunction recurs, replace the PCM. (Refer to [PCM REMOVAL/INSTALLATION ] in Service Information).