Diagnostic procedure

DTC P0300 - DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (Misfire related) been recorded?	Yes	Go to the next step.
1		No	Record FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Check for related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE OR STORED DTCs Turn key to OFF then ON (Engine off). Verify related pending code or stored DTCs. Is other DTCs present?	Yes	Go to appropriate DTC troubleshooting. (See DTC TABLE .)
3		No	Go to the next step.
4	VERIFY CURRENT INPUT SIGNAL STATUS (KEY TO ON/IDLE) Access ECT, IAT, MAF, RPM, TP, and VSS PIDs using the WDS or equivalent. (See PCM INSPECTION USING THE SST (WDS OR EQUIVALENT) ) Is there any signal that is far out of specification when ignition switch is ON and engine runs at idle?	Yes	Inspect suspected circuit and/or part according to inspection results. (See PCM INSPECTION USING THE SST (WDS OR EQUIVALENT) ) Then go to Step 21.
4		No	Go to the next step.
5	VERIFY CURRENT INPUT SIGNAL STATUS UNDER TROUBLE CONDITION Inspect PID while simulating FREEZE FRAME DATA condition. Is there any signal which causes drastic changes?	Yes	Inspect suspected circuit and/or part according to inspection results. (See PCM INSPECTION USING THE SST (WDS OR EQUIVALENT) .) Then go to Step 21.
5		No	Go to the next step.
6	INSPECT CMP SENSOR Inspect CMP sensor. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION .) Is CMP sensor okay?	Yes	Go to the next step.
6		No	Inspect installation condition and damages on timing belt and gears, repair faulty parts. If it is okay, replace CMP sensor. Then go to Step 21.
7	VERIFY CKP SENSOR INSTALLATION CONDITION Check for CKP sensor looseness. Is CKP sensor loosen?	Yes	Retighten CKP sensor, then go to Step 21.
7		No	Go to the next step.
8	INSPECT IGNITION COIL HARNESS Inspect the ignition coil related harness condition (intermittent open or short) for all cylinders. Are harness conditions normal?	Yes	Go to the next step.
8		No	Repair suspected wiring harnesses, then go to Step 21.
9	INSPECT IGNITION SYSTEM OPERATION Carry out Spark Test. (See SPARK TEST .) Is strong blue spark visible at each cylinder?	Yes	Go to the next step.
9		No	Repair or replace malfunctioning part according to spark test result. Then go to Step 21.
10	INSPECT POWER SUPPLY TERMINAL AT IGNITION COIL CONNECTOR Disconnect ignition coil connector. Turn key to ON (Engine off). Measure voltage between ignition coil terminal D (harness-side) and body ground. Is voltage reading B+?	Yes	Go to the next step.
10		No	Check for open circuit between ignition coil connector and ignition switch. Repair or replace wiring harness, then go to Step 21.
11	INSPECT IGNITION COIL RESISTANCE Check ignition coil resistance. (See IGNITION COIL INSPECTION .) Is coil resistance okay?	Yes	Go to step 21.
11		No	Replace ignition coil, then go to Step 21.
12	INSPECT MAF PID Start engine. Access MAF PID using the WDS or equivalent. Verify that MAF PID changes quickly according to race engine RPM. Is MAF PID response okay?	Yes	Go to the next step.
12		No	Replace mass airflow sensor, then go to Step 21.
13	INSPECT EXCESSIVE AIR SUCTION IN INTAKE AIR SYSTEM Inspect for air leakage at following: Between mass air flow sensor and throttle body Between throttle body and dynamic chamber Is there any malfunction?	Yes	Repair or replace suspected part, then go to Step 21.
13		No	Go to the next step.
14	INSPECT FUEL LINE PRESSURE Inspect fuel line pressure. (See FUEL LINE PRESSURE INSPECTION .) Is fuel line pressure okay?	Yes	Go to step 18.
14		No	If fuel line pressure is too low, go to the next step. If fuel line pressure is excess high, check as follows: Fuel pump maximum pressure (See FUEL LINE PRESSURE INSPECTION .) Fuel return line for clogged If all above are okay, replace pressure regulator. Then go to Step 21.
15	INSPECT FUEL PUMP MAXIMUM PRESSURE Inspect fuel pump maximum pressure. (See FUEL LINE PRESSURE INSPECTION .) Is fuel pump maximum pressure within 590-800 kPa {6.1-8.1 kgf/cm ² , 86-116 psi}?	Yes	Go to the next step.
15		No	Inspect fuel pump circuit for open or poor connection. Repair or replace suspected circuit, then go to Step 21. If okay, replace fuel pump, then go to Step 21.
16	INSPECT FUEL LINE FROM FUEL PUMP TO FUEL DELIVERY PIPE Visually inspect for fuel leakage in fuel line for any leakage. Is any fuel leakage found?	Yes	Replace suspected fuel line, then go to Step 21.
16		No	Inspect fuel filters for following: Restriction or clogging at fuel filter (high-pressure side). Foreign materials or stain inside fuel filter (low-pressure side) Perform following actions as result. If restriction or clogging is found at fuel filter (high-pressure side), replace fuel filter. If foreign materials or stain is found inside fuel filter (low-pressure side), clean of fuel tank and filter. If all items above are okay, replace pressure regulator. Then, go to Step 21.
17	INSPECT ENGINE COMPRESSION Inspect engine compression. (See COMPRESSION INSPECTION .) Is it normal?	Yes	Go to the next step.
17		No	Implement engine overhaul for repairs, then go to Step 21.
18	INSPECT OPERATION OF PURGE CONTROL SOLENOID VALVE Perform purge solenoid valve inspection. (See PURGE SOLENOID VALVE INSPECTION ) Is purge control solenoid valve okay?	Yes	Go to the next step.
18		No	Replace purge control solenoid valve, then go to Step 21.
19	INSPECT PCV VALVE OPERATION Turn the ignition switch off. Remove PCV valve and check valve operation. (See PCV VALVE INSPECTION .) Is PCV valve operation okay?	Yes	Replace PCV valve, then go to Step 21.
19		No	Go to the next step.
20	INSPECT OPERATION OF EGR VALVE Remove EGR valve. Visually check for stuck to open. Does EGR valve stuck to open?	Yes	Go to the next step.
20		No	Repair or replace EGR valve, then go to Step 21.
21	INSPECT SEALING OF ENGINE COOLANT PASSAGE WARNING: Removing radiator cap when radiator is hot is dangerous. Scalding coolant and steam may shoot out and cause serious injury. When removing radiator cap, wrap thick cloth around and turn it slowly. Remove radiator cap. Implement procedure to bleed air from engine coolant, then run engine at idle. Is there any small bubble which makes engine coolant white at filling opening? NOTE: Large bubbles are normal since they are remaining air coming out from engine coolant passage.	Yes	Air gets in from poor sealing on head gasket or other areas between combustion chamber and engine coolant passage. Repair or replace faulty parts, then go to the next step.
21		No	Go to the next step.
22	VERIFY TROUBLESHOOTING OF MISFIRE DTC COMPLETED Make sure to reconnect all disconnected connectors. Turn key to ON (Engine off). Clear the DTC from the memory using the WDS or equivalent. Start engine and perform DRIVE MODE 1. (See MODE 1 (PCM ADAPTIVE MEMORY PRODUCE DRIVE MODE) .) Is PENDING CODE for this DTC present?	Yes	Replace PCM, then go to the next step.
22		No	Go to the next step.
23	VERIFY AFTER REPAIR PROCEDURE Perform the "After Repair Procedure". (See AFTER REPAIR PROCEDURE .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
23		No	Troubleshooting completed.