Diagnostic Procedure

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EMISSION COMPLIANCE (PYUL) DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	VERIFY PCM DTCs Perform the DTC inspection for the PCM. (See DTC INSPECTION .) Are any DTCs displayed?	Yes	Repair or replace the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (PYUL)] .)
1		No	Go to the next step.
2	VERIFY DRIVE MODE CONDITION Verify that the drive mode is completed. Is the drive mode completed?	Yes	Go to the next step.
2		No	Perform the Drive Mode. (See OBD DRIVE MODE [PCM (PYUL)] .) Perform the repair completion verification 1.
3	INSPECT FOR ANY OTHER MALFUNCTION Can malfunction symptoms other than [EMISSION COMPLIANCE] be verified? (See SYMPTOM TROUBLESHOOTING [PYUL] ).	Yes	Perform symptom troubleshooting following the applicable symptom troubleshooting procedure. (See SYMPTOM TROUBLESHOOTING [PYUL] ).
3		No	Go to the next step.
4	VERIFY CO AND HC CONCENTRATION Verify CO and HC concentration. Is the CO or HC concentration excessive?	Yes	Go to Step 6. NOTE: If the HC concentration is normal and the CO concentration is excessive, a rich A/F can be considered the cause. If the CO concentration is normal and the HC concentration is excessive, a A/F lean can be considered the cause. If the CO and HC concentration is excessive, incomplete combustion or a rich A/F can be considered the cause.
4		No	Go to the next step.
5	VERIFY NOx CONCENTRATION Verify NOx concentration. Is the NOx concentration excessive?	Yes	Go to the next step.
5		No	Complete the symptom troubleshooting.
6	VERIFY IF MALFUNCTION CAUSED BY IGNITION TIMING MALFUNCTION Inspect the ignition timing. (Refer to [ENGINE TUNE-UP ] in Service Information). Is there any malfunction?	Yes	Inspect the following: Spark plug (Refer to [SPARK PLUG INSPECTION ] in Service Information). Ignition coil No. 1 (Refer to [IGNITION COIL INSPECTION ] in Service Information). Ignition coil No. 2 Ignition coil No. 3 Ignition coil No. 4 CMP sensor (Refer to [CAMSHAFT POSITION (CMP) SENSOR INSPECTION ] in Service Information). CKP sensor (Refer to [CRANKSHAFT POSITION (CKP) SENSOR INSPECTION ] in Service Information). If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1. If there is no malfunction: Perform the repair completion verification 1.
6		No	Go to the next step.
7	INSPECT PURGE CONTROL SYSTEM OPERATION Perform [Purge Control System Inspection]. (Refer to [PURGE SOLENOID VALVE INSPECTION ] in Service Information). Does the purge solenoid valve work properly?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning location and perform the repair completion verification 1.
8	INSPECT FUEL PRESSURE (HIGH-SIDE) Start the engine and warm it up completely. Access the PCM PID [FUEL_PRES] using the M-MDS at idle. (See PID/DATA MONITOR INSPECTION .) Is the PID value within specification? Specification: Approx. 10 MPa {102 kgf/cm² , 1450 psi}	Yes	Go to the next step.
8		No	Lower than specification: Inspect the following: Fuel leakage at the fuel line and fuel injector Fuel pump Perform [Fuel Pump (Low-pressure side) Operation Inspection]. (Refer to [FUEL PUMP UNIT INSPECTION ] in Service Information). Fuel pressure sensor (Refer to [FUEL PRESSURE SENSOR INSPECTION ] in Service Information). High pressure fuel pump (Refer to [HIGH PRESSURE FUEL PUMP INSPECTION ] in Service Information). If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1. If there is no malfunction: Go to the next step. Higher than specification: Inspect the following: Fuel line and fuel injector restriction Fuel pressure sensor (Refer to [FUEL PRESSURE SENSOR INSPECTION ] in Service Information). High pressure fuel pump (Relief valve clogged) (Refer to [HIGH PRESSURE FUEL PUMP INSPECTION ] in Service Information). Repair or replace the malfunctioning location and perform the repair completion verification 1.
9	INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE Inspect for leakage in intake-air system. (Refer to [INTAKE-AIR SYSTEM LOCATION INDEX ] in Service Information). Is there any leakage?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
9		No	Go to the next step.
10	INSPECT RESTRICTION IN VENTILATION HOSE Inspect for restriction in the ventilation hose. Is there any restriction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
10		No	Go to the next step.
11	VERIFY IF MALFUNCTION CAUSE IS CHARCOAL CANISTER Inspect the charcoal canister. (Refer to [CHARCOAL CANISTER INSPECTION ] in Service Information). Is the charcoal canister damaged?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1. (Refer to [CHARCOAL CANISTER REMOVAL/INSTALLATION ] in Service Information).
11		No	Go to the next step.
12	VERIFY IF MALFUNCTION CAUSED BY LACK OF ENGINE COOLANT Inspect the engine coolant amount. (Refer to [ENGINE COOLANT LEVEL INSPECTION ] in Service Information). Is there any malfunction?	Yes	Add engine coolant and verify that there is no engine coolant leakage. (Refer to [ENGINE COOLANT REPLACEMENT ] in Service Information). (Refer to [ENGINE COOLANT LEAKAGE INSPECTION ] in Service Information). If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1. If there is no malfunction: Perform the repair completion verification 1.
12		No	Go to the next step.
13	VERIFY CARBON ACCUMULATION CONDITION IN COMBUSTION CHAMBER Verify carbon accumulation condition in combustion chamber. Has carbon accumulated?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
13		No	Go to the next step.
14	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.
14		No	Inspect for the following engine internal parts: Cylinder Piston ring Improper intake valve timing Improper exhaust valve timing Such as cylinder head gasket If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification 1.
15	INSPECT TWC FOR RESTRICTION Inspect for restriction in the TWC. Is there any restriction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1. (Refer to [CATALYTIC CONVERTER (GPF) REMOVAL/INSTALLATION ] in Service Information).
15		No	Go to the next step.
16	INSPECT EXHAUST SYSTEM FOR LEAKAGE Visually inspect for exhaust gas leakage from the exhaust system. Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
16		No	Go to the next step.
17	VERIFY PCV VALVE FOR MALFUNCTION Inspect the applicable part. (Refer to [POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION ] in Service Information). Is the part normal?	Yes	Go to the next step.
17		No	Repair or replace the malfunctioning location and perform the repair completion verification 1. (Refer to [POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION ] in Service Information).
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED Measure CO, HC, and NOx concentration again. Is CO, HC, and NOx concentration within specification?	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.