DTC P0300:00 [MZR 1.3, MZR 1.5]

id0102f8703200

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 MIL 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 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 above malfunction condition 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
―  Brake switch 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
―  Ignition coil related wiring harness malfunction
―  Spark plug malfunction
―  Ignition coil malfunction
•  Excessive air suction in intake-air system (between MAF sensor and intake manifold)
―  Vacuum hoses damages or improper connection
―  Pipe malfunction
•  MAF sensor contamination
•  Fuel supply system malfunction or improper fuel line pressure
―  Fuel pump unit malfunction
―  Pressure regulator malfunction (built-into fuel pump unit)
―  Fuel leakage in fuel line between fuel distributor and fuel pump
―  Restricted fuel line blockage
―  Restricted fuel filter blockage
―  Fuel runout
•  Improper operation of variable valve timing control system
•  Improper operation of purge solenoid valve
•  Engine coolant leakage
•  Insufficient engine compression
•  Improper operation of EGR valve
•  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
•  Turn the ignition switch off, then to the ON position (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 1.3, MZR 1.5].)
No
Go to the next step.
4
VERIFY CURRENT INPUT SIGNAL STATUS (KEY TO ON/IDLE)
•  Access the following PIDs using the M-MDS:
―  BOO
―  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 runs at idle?
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) condition.
•  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 and damages on the timing belt 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 installation of CKP sensor.
•  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 1.3, MZR 1.5].)
8
INSPECT IGNITION SYSTEM OPERATION
•  Perform the Spark Test.
•  Is a strong blue spark visible at each cylinder?
Yes
Go to Step 12.
No
Go to the next step.
9
INSPECT IGNITION COIL AND RELATED WIRING HARNESS
•  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 22.
(See IGNITION COIL REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
No
Go to the next step.
10
INSPECT POWER SUPPLY TERMINAL AT IGNITION COIL CONNECTOR
•  Turn the ignition switch off.
•  Disconnect the ignition coil connector.
•  Turn the ignition switch to the ON position (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 for continuity between ignition coil terminal A (wiring harness-side) and PCM terminal 2D (wiring harness-side).
•  Repair or replace the wiring harness for a possible open circuit, if necessary.
Go to Step 22.
11
INSPECT SPARK PLUG
•  Inspect the spark plug.
•  Is there any malfunction?
Yes
Replace the spark plug, then go to Step 22.
(See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
No
Replace the ignition coil, then go to Step 22.
(See IGNITION COIL REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
12
INSPECT MAF SENSOR
•  Start the engine.
•  Access the MAF PID using the M-MDS.
•  Verify that the MAF PID value changes quickly while increasing (racing) the engine speed.
•  Is the MAF PID response 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 22.
No
Replace the MAF/IAT sensor, then go to Step 22.
(See MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
14
INSPECT FUEL LINE PRESSURE
•  Turn the ignition switch off.
Note
•  If the engine will not start, inspect the fuel line pressure with ignition switches to ON.
•  Inspect the fuel line pressure with the engine is 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
Go to Step 16.
15
INSPECT FUEL LINE LEAKAGE
•  Visually inspect for leakage from fuel line between fuel distributor and fuel pump.
•  Is there any leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 22.
No
Visually inspect for foreign materials or stain inside fuel filter (low-pressure side).
•  If there is any malfunction:
―  Clean the fuel tank and filter (low-pressure side).
•  If there is no malfunction:
―  Replace the fuel pump unit.
Go to Step 22.
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
•  Turn the ignition switch 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.
•  Turn the ignition switch to the ON position (engine off).
•  Perform the Active Command Modes Procedure and access the EVAPCP PID.
•  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 22.
(See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
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 22.
No
Go to the next step.
19
INSPECT ENGINE COMPRESSION
•  Inspect the engine compression.
•  Is there any malfunction?
Yes
Perform the engine overhaul for repairs, then go to Step 22.
No
Go to the next step.
20
INSPECT EGR VALVE OPERATION
•  Remove the EGR valve.
•  Visually inspect the EGR valve.
•  Is the EGR valve stuck open?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 22.
(See EGR VALVE REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
No
Go to the next step.
21
INSPECT PCV VALVE OPERATION
•  Turn the ignition switch 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, then go to the next step.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
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
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
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 1.3, MZR 1.5].)
No
DTC troubleshooting completed.