DTC P0300:00 [MZR 1.6]

id0102h3703200

DTC P0300:00

Random misfire detected
DETECTION CONDITION
•  The PCM monitors the CKP sensor input signal interval time. The PCM calculates the change of interval time for each cylinder. If change of interval time exceeds the preprogrammed criteria, the PCM detects 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 check engine light illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
•  The check engine light flashes if the PCM detects misfire which can damage the catalytic converter during first drive cycle.
•  PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is available.
•  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
―  Spark plug malfunction
―  Ignition coil related wiring harness malfunction
―  Ignition coil malfunction
―  Erratic signal to ignition coil
•  Excessive air suction in intake air system (between MAF sensor and intake manifold)
•  MAF sensor contamination
•  Fuel supply system malfunction or improper fuel line pressure
―  Fuel pump unit malfunction
―  Fuel pressure regulator (built-in fuel pump unit) malfunction
―  Fuel leakage in fuel line
―  Fuel line clogged
―  Fuel filter clogged
―  Fuel runout
•  Improper operation of variable valve timing control system
•  Purge solenoid valve malfunction
•  Engine internal malfunction
―  Engine coolant leakage to combustion chamber
―  Insufficient engine compression
•  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 off, then ON (engine off).
•  Verify the related PENDING CODE and stored DTCs using the M-MDS.
•  Are any other DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 1.6].)
No
Go to the next step.
4
VERIFY CURRENT INPUT SIGNAL STATUS (IGNITION SWITCH TO ON/IDLE)
•  Perform the PID/DATA Monitor and Record Procedure and 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 ON and the engine idles?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 21.
No
Go to the next step.
5
VERIFY CURRENT INPUT SIGNAL STATUS UNDER FREEZE FRAME DATA (MODE 2) CONDITION
•  Perform the PID/DATA Monitor and Record Procedure and access the same PIDs as in Step 4 under the FREEZE FRAME DATA (Mode 2) condition.
•  Is there any signal which causes drastic changes?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 21.
No
Go to the next step.
6
INSPECT CMP SENSOR
•  Inspect the CMP sensor.
•  Is there any malfunction?
Yes
Inspect the installation condition and damages on the timing chain and gears.
•  If there is a malfunction:
―  Repair or replace the malfunctioning part according to the inspection results.
•  If there is no malfunction:
―  Replace the CMP sensor.
Go to Step 21.
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 21.
(See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [MZR 1.6].)
8
INSPECT IGNITION SYSTEM OPERATION
•  Carry out the spark test.
•  Is the strong blue spark visible at each cylinder?
Yes
Go to Step 12.
No
Go to the next step.
9
INSPECT POWER SUPPLY TERMINAL AT IGNITION COIL CONNECTOR
•  Switch the ignition off.
•  Disconnect the ignition coil connector.
•  Switch the ignition ON (engine off).
•  Measure the voltage at the ignition coil terminal A (wiring harness-side).
•  Is the voltage B+?
Yes
Go to the next step.
No
Inspect the wiring harness between ignition coil terminal A and PCM terminal 2I for open circuit.
Repair or replace the wiring harness for a possible open circuit, then go to Step 21.
10
INSPECT IGNITION COIL AND RELATED WIRING HARNESS
•  Switch the ignition off.
•  Inspect the ignition coil and related wiring harness condition (intermittent open or short circuit) for all cylinders.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 21.
(See IGNITION COIL REMOVAL/INSTALLATION [MZR 1.6].)
No
Go to the next step.
11
INSPECT IGNITION COIL RESISTANCE
•  Inspect the ignition coil resistance.
•  Is the resistance normal?
Yes
Replace the spark plug, then go to Step 21.
(See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.6].)
No
Replace the ignition coil, then go to Step 21.
(See IGNITION COIL REMOVAL/INSTALLATION [MZR 1.6].)
12
INSPECT MAF SENSOR
•  Start the engine.
•  Perform the PID/DATA Monitor and Record Procedure and access the MAF PID using the M-MDS.
•  Verify that the MAF PID changes quickly according to race the engine RPM.
•  Is the MAF PID value normal?
Yes
Go to Step 14.
No
Go to the next step.
13
INSPECT EXCESSIVE AIR SUCTION IN INTAKE AIR SYSTEM
•  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 21.
No
Replace the MAF/IAT sensor, then go to Step 21.
(See MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION [MZR 1.6].)
14
INSPECT FUEL LINE PRESSURE
•  Inspect the fuel line pressure.
•  Is the fuel line pressure normal?
Yes
Go to Step 16.
No
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 21.
15
INSPECT FUEL LINE FROM FUEL PUMP TO FUEL DISTRIBUTOR
•  Visually inspect for fuel leakage in fuel line for any leakage.
•  Is there fuel leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 21.
No
Inspect the fuel filters for the following:
•  Foreign material or stain inside fuel filter (low-pressure side)
Perform the following actions depend on the result above.
•  If the foreign materials or stain is found inside the fuel filter (low-pressure side):
―  Clean the fuel tank and fuel filter (low-pressure side).
•  If normal:
―  Replace the fuel pump unit.
Go to Step 21.
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 21.
No
Go to the next step.
17
INSPECT PURGE SOLENOID VALVE OPERATION
•  Switch the ignition off.
•  Connect the vacuum pump to the purge solenoid valve and apply vacuum to the purge solenoid valve.
•  Verify that the purge solenoid valve holds vacuum.
•  Switch the ignition ON (engine off).
•  Perform the Active Command Modes Procedure and access the EVAPCP PID using the M-MDS.
•  Set duty value to 100% for the EVAPCP PID.
•  Apply vacuum while turning the purge solenoid valve from Off to On and simulating EVAPCP PID with 100% duty value.
•  Verify that the purge solenoid valve releases vacuum while the purge solenoid valve is turned ON.
•  Is there any malfunction?
Yes
Replace the purge solenoid valve, then go to Step 21.
(See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [MZR 1.6].)
No
Go to the next step.
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 21.
No
Go to the next step.
19
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 21.
No
Go to the next step.
20
INSPECT PCV VALVE OPERATION
•  Switch the ignition off.
•  Remove the PCV valve and the oil separator as a single unit.
•  Inspect the PCV valve operation.
•  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 [MZR 1.6].)
No
Replace the fuel. (Poor quality fuel is used.)
Go to the next step.
21
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Always reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the Drive Mode 01 (PCM Adaptive Memory Produce Drive Mode).
•  Is the PENDING CODE for this DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
22
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 1.6].)
No
DTC troubleshooting completed.