Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM IDLE LEARNING NOT PERFORMED Start the engine and warm it up completely. Idle the engine for 5 min or more. Does the symptom disappear?	Yes	Symptom troubleshooting is completed. (Cause of this symptom is that the idle learning for drive-by-wire control system is not completed.)
1		No	Go to the next step.
2	INSPECT RELATED PART CONDITION Inspect the following: Electrical connections External fuel shut off or accessory (such as kill switch, alarm) Fuel quality (such as proper octane, contamination, winter/summer blend) Vacuum leakage Fuses Ignition wiring No air leakage from intake air system PCM ground circuit (1E, 1F, 1G or 1BE) Proper sealing of intake manifold and components attached to intake manifold: such as EGR valve Smooth operation of throttle valve Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 2.
2		No	Go to the next step.
3	VERIFY PCM DTC Perform the PCM DTC inspection using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
3		No	Go to the next step.
4	VERIFY IF MALFUNCTION CAUSE IS OVERHEATING Is the engine overheating?	Yes	Go to the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING .)
4		No	Go to the next step.
5	INSPECT MAF SENSOR SIGNAL 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 MAF PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST .) Drive the vehicle during monitoring the MAF PID. Is the MAF PID value within the specification? (See PCM INSPECTION .)	Yes	Go to the next step.
5		No	Inspect for an open or short circuit in the MAF sensor and related wiring harness. Repair or replace the malfunctioning part according to the inspection results.
6	DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER NOTE: The following test is for the engine running rough at idle with A/C on concerns. If other symptoms exist, go to the next step. Connect a pressure gauge to the A/C low and high pressure side lines. Start the engine and idle it. Turn the A/C switch on. Measure the low side and high side pressures. Are the pressures within the specification? (See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
6		No	If the A/C is always on: Go to the symptom troubleshooting "NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY". (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY .) For other symptoms: Inspect the following: Refrigerant charging amount Condenser fan operation Repair or replace the malfunctioning part according to the inspection results.
7	VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL Visually inspect the CKP sensor and teeth of the crankshaft pulley. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION .) 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 IGNITION SYSTEM RELATED WIRING HARNESS Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Is there any malfunction?	Yes	Repair or replace the suspected wiring harness.
8		No	Go to the next step.
9	VERIFY SPARK PLUG CONDITION Inspect the spark plug condition. (See SPARK PLUG INSPECTION .) Is the spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect the fuel injector for restriction. Repair or replace the malfunctioning part according to the inspection results.
9		No	Install the spark plugs on original cylinders, then go to the next step.
10	INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION Perform the Drive-by-wire Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
10		No	Go to the next step.
11	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION .) Is there any malfunction?	Yes	Zero or low: Inspect the fuel pump relay and the fuel pump circuit. (See RELAY INSPECTION .) Inspect the fuel line for restriction. 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. (Pressure regulator or fuel pump malfunction) (See FUEL PUMP UNIT REMOVAL/INSTALLATION .) High: Replace the fuel pump unit. (Pressure regulator malfunction) (See FUEL PUMP UNIT REMOVAL/INSTALLATION .)
11		No	Go to the next step.
12	INSPECT FUEL SYSTEM FOR FUEL LEAKAGE Visually inspect for fuel leakage at the fuel injector O-ring and fuel line. Is the fuel line pressure held after the ignition is off?	Yes	Go to the next step.
12		No	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION .) If the fuel injector has malfunction: Replace the fuel injector. (See FUEL INJECTOR REMOVAL/INSTALLATION .) If the fuel injector is normal: Replace the fuel pump unit. (Check valve malfunction) (See FUEL PUMP UNIT REMOVAL/INSTALLATION .)
13	INSPECT LONG TERM FUEL TRIM Start the engine and idle it. Access the LONGFT1 PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST .) Measure the LONGFT1 PID at idle. Is the LONGFT1 PID value between -14 % and +14 % ?	Yes	Go to the next step.
13		No	Less than specification (too rich): Inspect the EVAP control system. Greater than specification (too lean): Inspect for air leakage at the intake air system components. If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction: Go to the next step.
14	DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from the purge solenoid valve side. Plug the open end of the vacuum hose. Switch the ignition to ON (engine off). Is the engine stall now eliminated?	Yes	Inspect the following: Purge solenoid valve (See PURGE SOLENOID VALVE INSPECTION .) EVAP control system (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Repair or replace the malfunctioning part according to the inspection results.
14		No	Go to the next step.
15	INSPECT EXHAUST SYSTEM Visually inspect the exhaust system part. (See ENGINE EXHAUST SYSTEM INSPECTION .) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
15		No	Go to the next step.
16	VISUALLY INSPECT CMP SENSOR AND PULSE WHEEL Visually inspect the CMP sensor and teeth of the camshaft. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION .) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
16		No	Go to the next step.
17	INSPECT EGR VALVE FOR STUCK Inspect the engine condition while tapping the EGR valve housing. Does the engine condition improve?	Yes	Clean or replace the EGR valve if necessary. (See EGR VALVE REMOVAL/INSTALLATION .)
17		No	Go to the next step.
18	INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION Perform the Variable Valve Timing Control System Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
18		No	Go to the next step.
19	INSPECT ENGINE COMPRESSION Inspect the engine compression. (See COMPRESSION INSPECTION .) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
19		No	Go to the next step.
20	INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR VALVE TIMING Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION .) Is there any malfunction?	Yes	Replace the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION .)
20		No	Inspect the valve timing. (See VARIABLE VALVE TIMING ACTUATOR INSPECTION .) Repair or replace the malfunctioning part according to the inspection results.
21	Verify test results. If normal, return to the diagnostic index to service any additional symptoms. (See ENGINE CONTROL SYSTEM SYMPTOM DIAGNOSTIC INDEX .) 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.