Diagnostic Procedure

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

EMISSION COMPLIANCE (SKYACTIV-G, US) DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	VERIFY PCM DTC Perform the DTC inspection for the PCM. (See DTC INSPECTION .) Are any DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-G (US))] .)
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-II DRIVE MODE [PCM (SKYACTIV-G (VIN M))] .) (See OBD-II DRIVE MODE [PCM (SKYACTIV-G (VIN L))] .) Go to repair completion verification.
3	INSPECT FOR ANY OTHER MALFUNCTION Can malfunction symptoms other than "EMISSION COMPLIANCE" be verified? (See SYMPTOM DIAGNOSTIC INDEX (US) .)	Yes	Go to the applicable symptom troubleshooting. (See SYMPTOM DIAGNOSTIC INDEX (US) .)
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	Symptom troubleshooting is completed.
6	VERIFY IF MALFUNCTION CAUSED BY IGNITION TIMING MALFUNCTION Inspect the ignition timing. (See ENGINE TUNE-UP [SKYACTIV-G (VIN M (US))] .) (See ENGINE TUNE-UP [SKYACTIV-G (VIN L (US))] .) Is there any malfunction?	Yes	Inspect the following: Spark plug (See SPARK PLUG INSPECTION [SKYACTIV-G (VIN M (US))] .) (See SPARK PLUG INSPECTION [SKYACTIV-G (VIN L (US))] .) Ignition coil/ion sensor No. 1 (See IGNITION COIL INSPECTION [SKYACTIV-G (VIN M (US))] .) (See IGNITION COIL INSPECTION [SKYACTIV-G (VIN L (US))] .) Ignition coil/ion sensor No. 2 Ignition coil/ion sensor No. 3 Ignition coil/ion sensor No. 4 CMP sensor (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [SKYACTIV-G (VIN M (US))] .) (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [SKYACTIV-G (VIN L (US))] .) CKP sensor (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [SKYACTIV-G (VIN M (US))] .) (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [SKYACTIV-G (VIN L (US))] .) If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification. If there is no malfunction: Go to repair completion verification.
6		No	Go to the next step.
7	INSPECT PURGE CONTROL SYSTEM OPERATION Perform the Purge Control System Inspection. (See PURGE SOLENOID VALVE INSPECTION [SKYACTIV-G (VIN M (US))] .) (See PURGE SOLENOID VALVE INSPECTION [SKYACTIV-G (VIN L (US))] .) 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.
8	INSPECT FUEL PRESSURE (HIGH-SIDE) Start the engine and warm it up completely. Access the FUEL_PRES PID using the M-MDS at idle. (See PID/DATA MONITOR INSPECTION .) Is the FUEL_PRES 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 the Fuel Pump (Low-pressure Side) Operation Inspection. (See FUEL PUMP UNIT INSPECTION [SKYACTIV-G (VIN M (US))] .) (See FUEL PUMP UNIT INSPECTION [SKYACTIV-G (VIN L (US))] .) Fuel pressure sensor (See FUEL PRESSURE SENSOR INSPECTION [SKYACTIV-G (VIN M (US))] .) (See FUEL PRESSURE SENSOR INSPECTION [SKYACTIV-G (VIN L (US))] .) High pressure fuel pump (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G (VIN M (US))] .) (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G (VIN L (US))] .) Higher than specification: Inspect the following: Fuel line and fuel injector restriction Fuel pressure sensor (See FUEL PRESSURE SENSOR INSPECTION [SKYACTIV-G (VIN M (US))] .) (See FUEL PRESSURE SENSOR INSPECTION [SKYACTIV-G (VIN L (US))] .) High pressure fuel pump (Relief valve clogged) (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G (VIN M (US))] .) (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G (VIN L (US))] .) Repair or replace the malfunctioning location and perform the repair completion verification.
9	INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE Inspect for leakage in intake-air system. Is there any leakage?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification.
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.
10		No	U.S.A. and CANADA: Go to the next step. Except (U.S.A. and CANADA): Go to Step 13.
11	VERIFY IF MALFUNCTION CAUSE IS CHARCOAL CANISTER MAIN Inspect the charcoal canister main. (See CHARCOAL CANISTER INSPECTION [SKYACTIV-G (VIN M (US))] .) (See CHARCOAL CANISTER INSPECTION [SKYACTIV-G (VIN L (US))] .) Is the charcoal canister main damaged?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification. (See CHARCOAL CANISTER REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .) (See CHARCOAL CANISTER REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
11		No	Go to the next step.
12	VERIFY IF MALFUNCTION CAUSE IS CHARCOAL CANISTER SUB Inspect the charcoal canister sub. (See CHARCOAL CANISTER INSPECTION [SKYACTIV-G (VIN M (US))] .) (See CHARCOAL CANISTER INSPECTION [SKYACTIV-G (VIN L (US))] .) Is the charcoal canister sub damaged?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification. (See CHARCOAL CANISTER REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .) (See CHARCOAL CANISTER REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
12		No	Go to Step 14.
13	VERIFY IF MALFUNCTION CAUSE IS CHARCOAL CANISTER Inspect the charcoal canister. (See CHARCOAL CANISTER INSPECTION [SKYACTIV-G (VIN M (US))] .) (See CHARCOAL CANISTER INSPECTION [SKYACTIV-G (VIN L (US))] .) Is the charcoal canister damaged?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification. (See CHARCOAL CANISTER REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .) (See CHARCOAL CANISTER REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
13		No	Go to the next step.
14	VERIFY IF MALFUNCTION CAUSED BY LACK OF ENGINE COOLANT Inspect the engine coolant level. (See ENGINE COOLANT LEVEL INSPECTION [SKYACTIV-G (VIN M (US))] .) (See ENGINE COOLANT LEVEL INSPECTION [SKYACTIV-G (VIN L (US))] .) Is there any malfunction?	Yes	Add engine coolant and verify that there is no engine coolant leakage. (See ENGINE COOLANT REPLACEMENT [SKYACTIV-G (VIN M (US))] .) (See ENGINE COOLANT REPLACEMENT [SKYACTIV-G (VIN L (US))] .) (See ENGINE COOLANT LEAKAGE INSPECTION [SKYACTIV-G (VIN M (US))] .) (See ENGINE COOLANT LEAKAGE INSPECTION [SKYACTIV-G (VIN L (US))] .) If there is any malfunction: Repair or replace the malfunctioning location and perform the repair completion verification. If there is no malfunction: Go to repair completion verification.
14		No	Go to the next step.
15	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.
15		No	Go to the next step.
16	INSPECT ENGINE COMPRESSION Measure the compression pressure for each cylinder. (See COMPRESSION INSPECTION [SKYACTIV-G (VIN M (US))] .) (See COMPRESSION INSPECTION [SKYACTIV-G (VIN L (US))] .) Are compression pressures within specification?	Yes	Go to the next step.
16		No	Inspect the following: Damaged valve seat Worn valve stem and valve guide Worn or stuck piston ring Worn piston, piston ring or cylinder Such as cylinder head gasket Improper intake valve timing Improper exhaust valve timing Repair or replace the malfunctioning location and perform the repair completion verification.
17	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. (See EXHAUST SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .) (See EXHAUST SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
17		No	Go to the next step.
18	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.
18		No	Go to the next step.
19	INSPECT PCV VALVE FOR MALFUNCTION Inspect the applicable part. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [SKYACTIV-G (VIN M (US))] .) (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [SKYACTIV-G (VIN L (US))] .) Is the part normal?	Yes	Go to the next step.
19		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .) (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
Repair completion verification	VERIFY SYMPTOM TROUBLESHOOTING COMPLETED Measure CO, HC, and NOx concentration again. Is CO, HC, and NOx concentration within specification?	Yes	Complete the symptom troubleshooting. (Explain repair contents to customer)
Repair completion verification		No	Repeat the inspection from Step 1.