DTC P0300:00 [MZR 1.8, MZR 2.0, MZR 2.5]

id0102f4703200

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 the misfire which can damage the catalytic converter during 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
―  Related connector or terminals malfunction
―  Related wiring harness malfunction
•  CMP sensor malfunction
•  CKP sensor looseness
•  Ignition system malfunction
―  Spark plug malfunction
―  Ignition coil malfunction
―  Ignition coil related wiring harness malfunction
•  Excessive air suction in intake air system (between MAF sensor and intake manifold)
•  MAF sensor malfunction
•  Fuel supply system malfunction or improper fuel line pressure
―  Fuel leakage in fuel line
―  Fuel line clogged
―  Fuel filter clogged
―  Pressure regulator malfunction (built-in fuel pump unit)
―  Fuel pump unit malfunction
―  Fuel runout
•  Improper operation of variable valve timing control system (EXCEPT MZR 1.8)
•  Purge solenoid valve malfunction
•  Engine malfunction
―  Engine coolant leakage 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 the 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/OR DTC
•  Switch the ignition to off, then to ON (engine off).
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Are any other PENDING CODEs and/or DTCs present?
Yes
Go to the applicable PENDING CODE or DTC inspection.
(See DTC TABLE [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
4
VERIFY CURRENT INPUT SIGNAL STATUS (KEY TO ON/IDLE)
•  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 the ignition is switched to ON and the engine idles?
Yes
Inspect the suspected sensor and related wiring harness.
Repair or replace the malfunctioning part according to the inspection results, then go to Step 22.
No
Go to the next step.
5
VERIFY CURRENT INPUT SIGNAL STATUS UNDER FREEZE FRAME DATA (MODE 2) CONDITION
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 same PIDs as in Step 4 while simulating under the FREEZE FRAME DATA (Mode 2) conditions.
•  Is there any signal which causes drastic changes?
Yes
Inspect the suspected sensor and related wiring harness.
Repair or replace the malfunctioning part according to the inspection results, then go to Step 22.
No
Go to the next step.
6
INSPECT CMP SENSOR
•  Inspect the CMP sensor.
•  Is there any malfunction?
Yes
Inspect the installation condition for damage to the timing chain and gears.
•  If there is any malfunction:
―  Repair or replace the malfunctioning part according to the inspection results.
•  If there is no malfunction:
―  Replace the CMP sensor.
Go to Step 22.
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 22.
(See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
8
INSPECT IGNITION SYSTEM OPERATION
•  Perform the Spark Test.
•  Is a strong blue spark visible at each cylinder?
Yes
Go to Step 11.
No
Go to the next step.
9
INSPECT SPARK PLUG
•  Inspect the spark plugs for all cylinders.
•  Is there any malfunction?
Yes
Replace the suspected spark plug, then go to Step 22.
(See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
10
INSPECT IGNITION COIL
•  Inspect the ignition coils for all cylinders.
•  Is there any malfunction?
Yes
Replace the suspected ignition coil, then go to Step 22.
(See IGNITION COIL REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Inspect the ignition coil related wiring harness condition (intermittent open or short) for all cylinders.
Repair or replace the suspected wiring harness, then go to Step 22.
11
VERIFY CURRENT INPUT SIGNAL STATUS OF MAF SENSOR
•  Start the engine.
•  Access the MAF PID using the M-MDS.
•  Race the engine and verify that the MAF PID value changes quickly according to change in the engine speed.
•  Is the MAF PID response normal?
Yes
Go to Step 13.
No
Go to the next step.
12
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 malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 22.
No
Replace the MAF/IAT sensor, then go to Step 22.
(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
13
INSPECT FUEL LINE PRESSURE
Note
•  If the engine will not start, inspect the fuel line pressure with ignition is switched to ON.
•  Inspect the fuel line pressure while the 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 too high:
•  Replace the fuel pump unit, then go to Step 22.
No
MZR 1.8:
•  Go to Step 17.
EXCEPT MZR 1.8:
•  Go to Step 16.
14
INSPECT FUEL LINE LEAKAGE
•  Visually inspect the leakage from fuel line between fuel injector and fuel pump unit.
•  Is there any leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 22.
No
Go to the next step.
15
INSPECT FUEL FILTER
•  Visually inspect the foreign materials or stain inside fuel filter (low-pressure side).
•  Is there any foreign materials or stain?
Yes
Clean the fuel tank and filter (low-pressure side), then go to Step 22.
No
Replace the fuel pump unit, then go to Step 22.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
16
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 22.
No
Go to the next step.
17
INSPECT PURGE SOLENOID VALVE OPERATION
•  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 22.
(See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
18
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 22.
No
Go to the next step.
19
INSPECT ENGINE COMPRESSION
•  Inspect the engine compression.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 22.
No
Go to the next step.
20
INSPECT EGR VALVE
•  Inspect the EGR valve.
•  Is there any malfunction?
Yes
Replace the EGR valve, then go to Step 22.
(See EGR VALVE REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
21
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, then go to the next step.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Poor quality fuel is used.
•  Replace the fuel, then go to the next step.
22
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the KOER self test.
•  Is the PENDING CODE for this DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
23
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 1.8, MZR 2.0, MZR 2.5].)
No
DTC troubleshooting completed.