DTC P0300 [WL-C, WE-C (Thailand, General (L.H.D. R.H.D.) specs.)]

id0102b0806500

DTC P0300

Random misfire detected
DETECTION CONDITION
•  The PCM monitors the CKP sensor input signal interval time. The PCM calculates the deviation of the interval time for each cylinder. If the deviation of the 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 and calculates the misfire ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, the PCM determines that a misfire, which can affect emission performance, has occurred.
POSSIBLE CAUSE
•  CKP sensor malfunction
•  CMP sensor malfunction
•  Fuel line clogged
•  Fuel filter clogged
•  Fuel leakage in fuel line
•  Fuel run out
•  Poor quality fuel
•  EGR valve malfunction
•  Related connector and terminal malfunction
•  Related wiring harness malfunction
•  Insufficient compression

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 been recorded?
Yes
go to the next step.
No
Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2
VERIFY RELATED REPAIR INFORMATION AVAILABILITY
•  Verify related service 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.
No
Go to the next step.
3
VERIFY RELATED PENDING CODE OR STORED DTC
•  Turn the engine switch off, then ON position (Engine off).
•  Verify the related PENDING CODE or stored DTCs using M-MDS.
•  Is other DTC present?
Yes
Go to appropriate DTC troubleshooting procedure.
(See DTC TABLE [WL-C, WE-C (Thailand, General (L.H.D. R.H.D.) specs.)].)
No
go to the next step.
4
VERIFY CURRENT INPUT SIGNAL STATUS UNDER TROUBLESHOOTING CONDITION
•  Access the BOO, ECT, IAT, MAF, RPM, APP, SEGRP and VSS PIDs using the M-MDS.
•  Is any signal that is far out of specification when the engine switch is at the ON position and the engine idles?
Yes
Inspect the suspected circuit or part or both according to the inspection results.
Then go to Step 12
No
Go to the next step.
5
VERIFY CURRENT INPUT SIGNAL STATUS UNDER TROUBLE CONDITION
•  Inspect the same PIDs as in Step 4 while simulating the FREEZE FRAME DATA condition.
•  Is there any signal which cause drastic changes?
Yes
Inspect the suspected circuit or part or both according to the inspection results.
Then go to Step 12
No
Go to the next step.
6
INSPECT CKP SENSOR
•  Inspect the CKP sensor and the pulse wheel.
•  Is there any malfunction?
Yes
Repair or replace the suspected part according to the inspection results, then go to Step 12
No
Go to the next step.
7
INSPECT CMP SENSOR
•  Inspect the CMP sensor.
•  Is there any malfunction?
Yes
Repair or replace the suspected part according to the inspection results, then go to Step 12
No
Go to the next step.
8
INSPECT OPERATION OF EGR VALVE
•  Remove the EGR valve.
•  Visually inspect if the EGR valve is stuck open. Is the EGR valve stuck open?
Yes
Repair or replace the EGR valve, then go to Step 12
No
go to the next step.
9
INSPECT FUEL LINE
•  Turn the engine switch off.
Inspect the fuel lines for fuel leakage or clogging.
Yes
Repair or replace the suspected fuel line, then go to Step 12
No
go to the next step.
10
INSPECT ENGINE COOLANT PASSAGE FOR ENGINE COOLANT LEAKAGE
•  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 12
No
go to the next step.
11
INSPECT ENGINE COMPRESSION
•  Inspect the engine compression for the suspected cylinder.
Is the engine compression normal?
Yes
go to the next step.
No
Overhaul the engine, then go to the next step.
12
VERIFY TROUBLESHOOTING OF MISFIRE DTC COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Start the engine.
•  Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [WL-C, WE-C].)
No
go to the next step.
13
VERIFY AFTER REPAIR PROCEDURE
•  Perform "After Repair Procedure".
•  Are any DTCs present?
Yes
Go to the applicable DTC troubleshooting.
(See DTC TABLE [WL-C, WE-C (Thailand, General (L.H.D. R.H.D.) specs.)].)
No
Troubleshooting completed.