Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	INSPECT RELATED PART CONDITION Inspect the following: Vacuum leakage Proper fuel quality (such as proper octane, contamination, winter/summer blend) Loose bands on intake air system Cracks on intake air system parts Intake air system restriction (such as air cleaner element, fresh air duct) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 1.
1		No	Go to the next step.
2	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 .)
2		No	Go to the next step.
3	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 .)
3		No	Go to the next step.
4	DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER Disconnect the vacuum hose from purge solenoid valve and plug opening end of vacuum hose. Switch the ignition to ON (engine off). Is the starting condition improved?	Yes	Inspect if the purge solenoid valve is stuck open. (See PURGE SOLENOID VALVE INSPECTION .) Repair or replace the malfunctioning part according to the inspection results.
4		No	Go to the next step.
5	INSPECT MAF SENSOR Inspect the MAF sensor for the following: Contamination MAF sensor terminal B voltage (ground circuit) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
5		No	Go to the next step.
6	INSPECT PCM FOR POOR GROUND Verify the PCM ground point condition. Is there any ground point loose or lifting in the PCM?	Yes	Repair the ground point.
6		No	Go to the next step.
7	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.
7		No	Go to the next step.
8	INSPECT IGNITION SYSTEM OPERATION Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to the spark test result.
9	VERIFY SPARK PLUG CONDITION Verify the spark plug conditions when the spark plug removed in Step 8. (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 CKP SENSOR AND PULSE WHEEL Visually inspect the CKP sensor and teeth of crankshaft pulley. (See CRANKSHAFT POSITION (CKP) SENSOR 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	DETERMINE IF MALFUNCTION CAUSE IS DRIVE-BY-WIRE CONTROL SYSTEM OR OTHER Attempt to start the engine at part throttle. Does the engine run smoothly at part throttle?	Yes	Inspect the drive-by-wire control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION .) Repair or replace the malfunctioning part according to the inspection results.
11		No	Go to the next step.
12	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 .)
12		No	Go to the next step.
13	INSPECT FUEL LINE HOLD PRESSURE FOR FUEL LEAKAGE Is the fuel line pressure held after ignition is off? (See FUEL LINE PRESSURE INSPECTION .)	Yes	Go to the next step.
13		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 .)
14	INSPECT EXHAUST SYSTEM Visually inspect the exhaust system part. Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
14		No	Go to the next step.
15	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 .)
15		No	Go to the next step.
16	INSPECT STARTING SYSTEM Inspect the starting system. (See STARTER INSPECTION .) Is there any malfunction?	Yes	Repair or replace components as required.
16		No	Inspect for loose connectors or poor terminal contact. If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction: Remove the EGR valve and visually inspect for a mechanically stuck EGR valve. (See EGR VALVE REMOVAL/INSTALLATION .) Repair or replace the malfunctioning part according to the inspection results.
17	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.