Manual pages - MX5 Manual | Mazda MX5 (Mk4) 2015+

NO.15 EMISSION COMPLIANCE [SKYACTIV-G 2.0]

EMISSION COMPLIANCE

DESCRIPTION

Fails emissions test.

POSSIBLE CAUSE

Engine overheating

Cooling system malfunction

PCM DTC is stored

Incorrect fuel injection timing

Incorrect ignition timing

Spark plug malfunction

Ignition coil malfunction

Purge solenoid valve malfunction

Inadequate fuel pressure

Fuel leakage at the fuel line and/or fuel injector

Fuel pressure sensor or related circuit malfunction

High pressure fuel pump malfunction

Spill valve control solenoid valve control circuit malfunction (damage to driver in PCM caused by short circuit to ground system)

Spill valve control solenoid valve (built-into high pressure fuel pump) malfunction

Relief valve (built-into high pressure fuel pump) malfunction

Fuel line restriction

Fuel pump unit malfunction

Air leakage from intake-air system

Vacuum lines leakage or blockage

Charcoal canister damage

Improper engine coolant level

Excessive carbon built-up in combustion chamber

Improper engine compression

Improper intake valve timing

Improper exhaust valve timing

Exhaust system and/or TWC restriction

Exhaust gas leakage from the exhaust system

TWC malfunction (PCM DTC is stored.)

Positive crankcase ventilation system malfunction

PCV valve malfunction or incorrect valve installation

Clogging in positive crankcase ventilation system hoses (PCV valve hose, ventilation hose)

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.

CAUTION:

Verify the malfunction symptom according to not only the PID value but also the symptom troubleshooting.

Related PIDs

Item (definition)	Unit/Condition	Definition	Condition/Specification (Reference)
FUEL_PRES	KPa , mBar , psi, in H20	Fuel pressure input from fuel pressure sensor	Displays fuel pressure
FUEL_PRES	V	Fuel pressure sensor voltage	Ignition switched ON (engine off) Fuel pressure is approx. 3.6 MPa {37 kgf/cm², 522 psi}: Approx. 1.01 V (ECT is 92 °C {198 °F}) Idle (after warm up) Fuel pressure is approx. 3.45 MPa {35.2 kgf/cm², 500 psi}: Approx. 1 V (ECT is 92 °C {198 °F}) Racing (Engine speed is 2,000 rpm) Fuel pressure is approx. 3.21 MPa {32.7 kgf/cm², 466 psi}: Approx. 0.96 V (ECT is 86 °C {187 °F}) Racing (Engine speed is 4,000 rpm) Fuel pressure is approx. 5.59 MPa {57.0 kgf/cm², 811 psi}: Approx. 1.29 V (ECT is 84 °C {183 °F})
LOAD	%	Ratio of actual amount of intake air to the maximum air charging amount (mass volume) of cylinder	Idle (after warm up): Approx. 27.05% (ECT is 91 °C {196 °F}) Racing (engine speed is 2,000 rpm): Approx. 16.86% (ECT is 89 °C {192 °F}) Racing (engine speed is 4,000 rpm): Approx. 17.64% (ECT is 87 °C {189 °F})

Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM DTC 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	VERIFY DRIVE MODE CONDITION Verify that the drive mode is completed. Is the drive mode completed?	Yes	Go to the next step.
		No	Perform the Drive Mode. (See OBD-II DRIVE MODE [PCM (SKYACTIV-G 2.0)].)
3	INSPECT FOR ANY OTHER MALFUNCTION Can malfunction symptoms other than “NO.15 EMISSION COMPLIANCE” be verified? (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.0].)	Yes	Go to the applicable symptom troubleshooting. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.0].)
		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.
		No	Go to the next step.
5	VERIFY NOx CONCENTRATION Verify NOx concentration. Is the NOx concentration excessive?	Yes	Go to the next step.
		No	Symptom troubleshooting is completed.
6	VERIFY IF MALFUNCTION CAUSED BY IGNITION TIMING MALFUNCTION Inspect the ignition timing. (See ENGINE TUNE-UP [SKYACTIV-G 2.0].) Is there any malfunction?	Yes	Inspect the following: Spark plug (See SPARK PLUG INSPECTION [SKYACTIV-G 2.0].) Ignition coil/ion sensor No.1 (See IGNITION COIL INSPECTION [SKYACTIV-G 2.0].) (See ION SENSOR INSPECTION [SKYACTIV-G 2.0].) Ignition coil/ion sensor No.2 (See IGNITION COIL INSPECTION [SKYACTIV-G 2.0].) (See ION SENSOR INSPECTION [SKYACTIV-G 2.0].) Ignition coil/ion sensor No.3 (See IGNITION COIL INSPECTION [SKYACTIV-G 2.0].) (See ION SENSOR INSPECTION [SKYACTIV-G 2.0].) Ignition coil/ion sensor No.4 (See IGNITION COIL INSPECTION [SKYACTIV-G 2.0].) (See ION SENSOR INSPECTION [SKYACTIV-G 2.0].) If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results, then go to Step 18. If there is no malfunction: Go to Step 18.
		No	Go to the next step.
7	INSPECT PURGE CONTROL SYSTEM OPERATION Perform the Purge Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.0].) Does the purge solenoid valve work properly?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning part according to the inspection results, then go to Step 18.
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 ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].) Is the FUEL_PRES PID value approx. 3 MPa {31 kgf/cm², 435 psi}?	Yes	Go to the next step.
		No	Lower than 3 MPa {31 kgf/cm², 435 psi}: Inspect the following: Fuel leakage at the fuel line and fuel injector Fuel pump Perform the Fuel Pump (Low-pressure Side) Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.0].) Fuel pressure sensor (See FUEL PRESSURE SENSOR INSPECTION [SKYACTIV-G 2.0].) High pressure fuel pump (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G 2.0].) Higher than 3 MPa {31 kgf/cm², 435 psi}: Inspect the following: Fuel line and fuel injector restriction Fuel pressure sensor (See FUEL PRESSURE SENSOR INSPECTION [SKYACTIV-G 2.0].) High pressure fuel pump (Relief valve clogged) Repair or replace the malfunctioning part according to the inspection results, then go to Step 18.
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 part according to the inspection results, then go to Step 18.
		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 part according to the inspection results, then go to Step 18.
		No	Go to the next step.
11	VERIFY IF MALFUNCTION CAUSE IS CHARCOAL CANISTER Inspect the charcoal canister. (See CHARCOAL CANISTER INSPECTION [SKYACTIV-G 2.0].) Is the charcoal canister damaged?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 18. (See CHARCOAL CANISTER REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)
		No	Go to the next step.
12	VERIFY IF MALFUNCTION CAUSED BY LACK OF ENGINE COOLANT Inspect the engine coolant level. (See ENGINE COOLANT LEVEL INSPECTION [SKYACTIV-G 2.0].) Is there any malfunction?	Yes	Add engine coolant and verify that there is no engine coolant leakage. (See ENGINE COOLANT REPLACEMENT [SKYACTIV-G 2.0].) (See ENGINE COOLANT LEAKAGE INSPECTION [SKYACTIV-G 2.0].) If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results, then go to Step 18. If there is no malfunction: Go to Step 18.
		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 part according to the inspection results, then go to Step 18.
		No	Go to the next step.
14	INSPECT ENGINE COMPRESSION Measure the compression pressure for each cylinder. (See COMPRESSION INSPECTION [SKYACTIV-G 2.0].) Are compression pressures within specification?	Yes	Go to the next step.
		No	Inspect the following: Damaged valve seat Worn valve stem and valve guide Worn or stuck piston ring Worn piston, piston ring or cylinder Improper intake valve timing Improper exhaust valve timing Repair or replace the malfunctioning part according to the inspection results, then go to Step 18.
15	INSPECT TWC FOR RESTRICTION Inspect for restriction in the TWC. Is there any restriction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 18. (See EXHAUST SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)
		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 part according to the inspection results, then go to Step 18.
		No	Go to the next step.
17	INSPECT PCV VALVE Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [SKYACTIV-G 2.0].) Is there any malfunction?	Yes	Replace the PCV valve, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)
		No	Go to the next step.
18	VERIFY SYMPTOM TROUBLESHOOTING COMPLETED Measure CO, HC, and NOx concentration again. Is CO, HC, and NOx concentration within specification?	Yes	Symptom troubleshooting is completed.
		No	Repeat the inspection from Step 1.

< Previous Next >

Knowledge Base

NO.15 EMISSION COMPLIANCE [SKYACTIV-G 2.0]