DTC P0300:00 [LF, L5]

id0102c8703200

DTC P0300:00

Random misfire detected
DETECTION CONDITION
•  The PCM monitors CKP sensor input signal interval time. The PCM calculates the change of interval time for each cylinder. If the change of interval time exceeds the preprogrammed criteria, the PCM detects a misfire in the corresponding cylinder. While the engine is running, the PCM counts the number of misfires that occurred at 200 crankshaft revolutions and 1,000 crankshaft revolutions and calculates the misfire ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, the PCM determines that a misfire, which can damage the catalytic converter or affect emission performance, has occurred.
Diagnostic support note
•  This is a continuous monitor (misfire).
•  The MIL illuminates if the PCM detects the misfire which affects emission performance in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
•  The MIL flashes if the PCM detects a misfire which can damage the catalytic converter during the first drive cycle.
•  PENDING CODE is available if the PCM detects the misfire which affects emission performance during first drive cycle.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  Erratic signal to PCM
―  APP sensor signal malfunction
―  ECT sensor signal malfunction
―  IAT sensor signal malfunction
―  MAF sensor signal malfunction
―  CKP sensor signal malfunction
―  TP sensor signal malfunction
―  VSS signal malfunction
•  CMP sensor malfunction
•  CKP sensor looseness
•  Ignition system malfunction
―  Ignition coil related wiring harness malfunction
―  Spark plug malfunction
―  Ignition coil malfunction
•  MAF sensor malfunction
•  Excessive air suction in intake air system (between MAF sensor and intake manifold)
•  Fuel supply system malfunction or improper fuel line pressure
―  Fuel leakage in fuel line
―  Fuel line clogged
―  Fuel filter clogged
―  Fuel pressure regulator (built-in fuel pump unit) malfunction
―  Fuel pump unit malfunction
―  Fuel runout
•  Improper operation of variable valve timing control system
•  Purge solenoid valve malfunction
•  Base engine malfunction
―  Leakage engine coolant to combustion chamber
―  Insufficient engine compression
•  EGR valve malfunction
•  PCV valve malfunction
•  Poor quality fuel
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED
•  Have the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (misfire related) been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
VERIFY RELATED PENDING CODE AND STORED DTC
•  Switch the ignition to off, then to ON (engine off).
•  Perform the DTC Reading Procedure and Pending Trouble Code Access Procedure.
•  Are any other DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [LF, L5].)
No
Go to the next step.
4
VERIFY CURRENT INPUT SIGNAL STATUS (KEY TO ON/IDLE)
•  Connect the M-MDS to the DLC-2.
•  Access the following PIDs using the M-MDS.
―  APP1
―  APP2
―  ECT
―  IAT
―  MAF
―  RPM
―  TP REL
―  VSS
•  Is there any signal that is far out of specification when switch the ignition to ON and the engine idles?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 20.
No
Go to the next step.
5
VERIFY CURRENT INPUT SIGNAL STATUS UNDER FREEZE FRAME DATA (MODE 2) CONDITION
•  Connect the M-MDS to the DLC-2.
•  Access the following PIDs using the M-MDS under the FREEZE FRAME DATA (Mode 2) condition.
―  APP1
―  APP2
―  ECT
―  IAT
―  MAF
―  RPM
―  TP REL
―  VSS
•  Is there any signal which causes drastic changes?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 20.
No
Go to the next step.
6
INSPECT CMP SENSOR
•  Inspect the CMP sensor.
•  Is there any malfunction?
Yes
Replace the CMP sensor, then go to Step 20.
(See CAMSHAFT POSITION (CMP) SENSOR REMOVAL/INSTALLATION [LF, L5].)
No
Go to the next step.
7
INSPECT INSTALLATION OF CKP SENSOR
•  Inspect if the CKP sensor is loosely installed.
•  Is the CKP sensor installed securely?
Yes
Go to the next step.
No
Retighten the CKP sensor, then go to Step 20.
(See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [LF, L5].)
8
INSPECT IGNITION COIL RELATED WIRING HARNESS
•  Inspect the ignition coil related wiring harness condition (intermittent open or short) for all cylinders.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning wiring harness, then go to Step 20.
No
Go to the next step.
9
INSPECT IGNITION SYSTEM OPERATION
•  Carry out the spark test.
•  Is strong blue spark visible at each cylinder?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results, then go to Step 20.
10
VERIFY PID DATA FOR MAF SENSOR MALFUNCTION
•  Connect the M-MDS to the DLC-2.
•  Access the MAF PID using the M-MDS.
•  Race the engine and verify that the MAF PID changes quickly according to change in the engine speed.
•  Is the MAF PID response normal?
Yes
Go to Step 12.
No
Go to the next step.
11
INSPECT INTAKE AIR SYSTEM FOR AIR SUCTION
•  Inspect for air leakage between the following:
―  MAF sensor and throttle body
―  Throttle body and intake manifold
Note
•  Engine speed may change when rust penetrating agent is sprayed on the air suction area.
•  Is there any leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 20.
No
Replace the MAF/IAT sensor, then go to Step 20.
(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [LF, L5].)
12
INSPECT FUEL LINE PRESSURE
•  Switch the ignition to off.
Note
•  If engine will not start, inspect fuel line pressure with ignition is switched to ON.
•  Inspect fuel line pressure while engine running.
•  Is there any malfunction?
Yes
If the fuel line pressure is too low:
•  Go to the next step.
If the fuel line pressure is excess high:
•  Replace the fuel pump unit, then go to Step 20.
No
Go to Step 14.
13
INSPECT FUEL LINE FROM FUEL PUMP TO FUEL INJECTOR
•  Visually inspect the leakage from fuel line.
•  Is there any leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 20.
No
Inspect fuel filters for following:
•  Foreign material or stain inside fuel filter (low-pressure side)
Perform the following actions depend on the result above.
•  If foreign materials or stain is found inside fuel filter (low-pressure side):
―  Clean the fuel tank and filter (low-pressure side).
•  If normal:
―  Replace the fuel pump unit.
Go to Step 20.
14
INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION
•  Perform the Variable Valve Timing Control System Operation Inspection.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 20.
No
Go to the next step.
15
VERIFY SIMULATION ITEM FOR PURGE SOLENOID VALVE MALFUNCTION
•  Switch the ignition to off.
•  Connect the vacuum pump to the purge solenoid valve and apply vacuum to the solenoid.
•  Verify that the solenoid holds vacuum.
•  Switch the ignition to ON (engine off).
•  Access the EVAPCP PID of simulation item using the M-MDS.
•  Set the purge solenoid value to 100% for the EVAPCP PID.
•  Verify that the purge solenoid value releases vacuum while the 100% for the EVAPCP PID.
•  Is the purge solenoid valve operation normal?
Yes
Go to the next step.
No
Replace the purge solenoid valve, then go to Step 20.
(See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [LF, L5].)
16
INSPECT SEALING OF ENGINE COOLANT PASSAGE
•  Perform the “ENGINE COOLANT LEAKAGE INSPECTION”.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 20.
No
Go to the next step.
17
INSPECT ENGINE COMPRESSION
•  Inspect the engine compression.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning parts according to the inspection results, then go to Step 20.
No
Go to the next step.
18
INSPECT EGR VALVE
•  Inspect the EGR valve.
•  Is there any malfunction?
Yes
Replace the EGR valve, then go to Step 20.
(See EGR VALVE REMOVAL/INSTALLATION [LF, L5].)
No
Go to the next step.
19
INSPECT PCV VALVE OPERATION
•  Switch the ignition to off.
•  Remove the PCV valve.
•  Inspect the PCV valve.
•  Is there any malfunction?
Yes
Replace the PCV valve and the oil separator as a single unit, then go to the next step.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [LF, L5].)
No
Poor quality fuel is used.
•  Replace the fuel, then go to the next step.
20
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Start the engine and warm it up completely.
•  Perform the Pending Trouble Code Access Procedure.
•  Is the PENDING CODE for this DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [LF, L5].)
No
Go to the next step.
21
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [LF, L5].)
No
DTC troubleshooting completed.