Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY EXHAUST COLOR What color is smoke coming from the exhaust system?	Blue	Burning oil is indicated. Go to the next step.
		White	Water in combustion is indicated. Go to Step 4.
		Black	Rich fuel mixture is indicated. Go to Step 5.
2	INSPECT PCV VALVE Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Replace the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
2		No	Go to the next step.
3	INSPECT ENGINE INTERNAL PARTS Inspect for the following engine internal parts: Damaged valve guide, stems or valve seals Blocked oil drain passage in cylinder head Piston ring is not seated, seized or worn Damage cylinder bore Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
3		No	Engine internal parts are normal. If other driveability symptoms are present: Return to the diagnostic index to service additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5] .)
4	INSPECT ENGINE FOR ENGINE COOLANT LEAKAGE Does the cooling system hold the coolant pressure? (See ENGINE COOLANT LEAKAGE INSPECTION [SKYACTIV-G 2.5] .)	Yes	Inspect the following: Cylinder head gasket leakage Intake manifold gasket leakage Cracked or porous engine block Repair or replace the malfunctioning part according to the inspection results. If other driveability symptoms are present: Return to the diagnostic index to service additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5] .)
4		No	Inspect for the cause. Repair or replace the malfunctioning part according to the inspection results.
5	VERIFY CURRENT INPUT SIGNAL STATUS CAUTION: While performing this step, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. Access the following PIDs using the M-MDS: (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5] .) APP1 APP2 ECT IAT MAF MAP MAP_V TP_REL O2S11 O2S12 SHRTFT1 LONGFT1 Monitor the PIDs under the black smoke appeared engine condition. Do the PIDs indicate normal according to engine conditions? (See PCM INSPECTION [SKYACTIV-G 2.5] .)	Yes	Go to the next step.
5		No	APP1, APP2 PIDs are not as specified: Inspect the APP sensor. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [SKYACTIV-G 2.5] .) ECT PID is not as specified: Inspect the ECT sensor No. 1. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [SKYACTIV-G 2.5] .) IAT PID is not as specified: Inspect the IAT sensor No. 1. (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [SKYACTIV-G 2.5] .) MAF PID is not as specified: Inspect the MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [SKYACTIV-G 2.5] .) MAP, MAP_V PIDs are not as specified: Inspect the MAP sensor. (See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION [SKYACTIV-G 2.5] .) TP_REL PID is not as specified: Inspect the TP sensor. (See THROTTLE POSITION (TP) SENSOR INSPECTION [SKYACTIV-G 2.5] .) O2S11, SHRTFT1, LONGFT1 PIDs are not as specified: Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [SKYACTIV-G 2.5] .) O2S12 PID is not as specified: Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [SKYACTIV-G 2.5] .) Repair or replace the malfunctioning part according to the inspection results. If the malfunction remains: Perform the "INTERMITTENT CONCERN TROUBLESHOOTING" procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING [SKYACTIV-G 2.5] .)
6	INSPECT FUEL INJECTOR OPERATION Perform the Fuel Injector Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.5] .) Do the fuel injectors operate properly?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning part according to the inspection results.
7	INSPECT INTAKE AIR SYSTEM Inspect the following for intake-air system: Air cleaner restriction Collapsed or restricted air hose Leakage at engine intake manifold Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
7		No	Go to the next step.
8	INSPECT EXHAUST SYSTEM FOR LEAKAGE Visually inspect for exhaust gas leakage from exhaust manifold. Is there any leakage?	Yes	Repair or replace the malfunctioning part according to the inspection results.
8		No	Go to the next step.
9	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 [SKYACTIV-G 2.5] .) Is the FUEL_PRES PID value approx. 3 MPa {31 kgf/cm ² , 435 psi} ?	Yes	Go to Step 13.
9		No	Lower than 3 MPa {31 kgf/cm ² , 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 2.5] .) Fuel pressure sensor (See FUEL PRESSURE SENSOR INSPECTION [SKYACTIV-G 2.5] .) High pressure fuel pump (See HIGH PRESSURE FUEL PUMP INSPECTION [SKYACTIV-G 2.5] .) If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction: Go to Step 12. Higher than 3 MPa {31 kgf/cm ² , 435 psi} : Go to the next step.
10	DETERMINE IF MALFUNCTION CAUSE IS FUEL PRESSURE SENSOR OR HIGH PRESSURE FUEL PUMP Is the vehicle acceleration performance normal?	Yes	Go to the next step.
10		No	Go to Step 12.
11	INSPECT FUEL PRESSURE SENSOR Inspect the fuel pressure sensor. (See FUEL PRESSURE SENSOR INSPECTION [SKYACTIV-G 2.5] .) Is there any malfunction?	Yes	Replace the fuel distributor. (See FUEL INJECTOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
11		No	Go to Step 13.
12	INSPECT SPILL VALVE CONTROL SOLENOID VALVE CONTROL CIRCUIT FOR SHORT TO GROUND Switch the ignition off. Disconnect the high pressure fuel pump and PCM connectors. Inspect for continuity between high pressure fuel pump terminal A (wiring harness-side) and body ground. Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between high pressure fuel pump terminal A and PCM terminal 1EE. If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. If the malfunction remains: Replace the PCM. (damage to driver in PCM) (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
12		No	Replace the high pressure fuel pump. (See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
13	INSPECT FUEL PRESSURE (LOW-SIDE) Connect the fuel pressure gauge between fuel pump and high pressure fuel pump. Measure the low side fuel pressure. (See FUEL LINE PRESSURE INSPECTION [SKYACTIV-G 2.5] .) Is the low side fuel pressure within specification? Specification: 405- 485 kPa {4.13 - 4.94 kgf/cm ² , 58.8 - 70.3 psi}	Yes	Go to the next step.
13		No	Inspect the following: Fuel line restriction Fuel filter clogged If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
14	INSPECT IGNITION SYSTEM OPERATION NOTE: Because the malfunction may have been resolved by removing the carbon adhered to the spark plug during the spark inspection for the spark plug, verify that the repairs have been completed. Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.5] .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
14		No	Repair or replace the malfunctioning part according to the inspection results.
15	INSPECT IF MALFUNCTION CAUSE IS ENGINE COMPRESSION OR INJECTOR DRIVER (PCM INTEGRATED) Measure the compression pressure for each cylinder. (See COMPRESSION INSPECTION [SKYACTIV-G 2.5] .) Are compression pressures within specification? Specification: Compression Standard: 954 kPa {9.7 3 kgf/cm ² , 138 psi} (300 rpm) Minimum: 7 63 kPa {7.7 8 kgf/cm ² , 111 psi} (300 rpm) Maximum difference between cylinders: 161 kPa {1.64 kgf/cm ² , 23.4 psi} (3 00 rpm) NOTE: Because the SKYACTIV-G 2.5 retards the intake valve closing timing, compression pressure is low.	Yes	Injector driver malfunction. Replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .) If the problem remains, overhaul the engine.
15		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 Service if necessary.
16	Verify the test results. If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5] .) If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If the vehicle is repaired, troubleshooting is completed. If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.