Dtc P0300 - Mazda Mazda6 Workshop Manual Supplement

DTC P0300

DTC P0300 Random misfire detection
• PCM monitors CKP sensor input signal interval time. PCM calculates change of interval time for each
DETECTION
CONDITION cylinder. If the interval time exceeds preprogrammed criteria, PCM determines random misfire detection.
• Fuel leakage or clogged in fuel line
• Fuel injector malfunction
• CKP sensor malfunction
POSSIBLE
• CMP sensor malfunction
CAUSE
• Inadequate engine compression
• PCM malfunction
Diagnostic procedure
STEP
1 VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
• Check for related Service Information
availability.
• Is any related repair information available?
2 FOLLOW OTHER DETECTED DTC FIRST
• Turn engine switch to OFF.
• Start engine.
• Has P0200 been detected?
3 INSPECT FUEL LINE
• Turn engine switch to OFF.
• Inspect for fuel leakage or clogs in following
fuel lines for each cylinder:
— Common rail and fuel injector.
— Fuel injector and fuel tank.
•
Is there any malfunction?
4 INSPECT FUEL INJECTOR
• Inspect fuel injector.
(See F2–56 FUEL INJECTOR
• Is there any malfunction?
5 INSPECT CKP SENSOR
• Inspect CKP sensor.
(See F2–82 CRANKSHAFT POSITION (CKP)
SENSOR INSPECTION)
• Is there any malfunction?
6 INSPECT CMP SENSOR
• Inspect CMP sensor.
(See F2–80 CAMSHAFT POSITION (CMP)
SENSOR INSPECTION)
• Is there any malfunction?
7 INSPECT ENGINE COMPRESSION
• Inspect engine compression.
(See B2–8 COMPRESSION
• Is there any malfunction?
8 VERIFY TROUBLESHOOTING OF DTC P0300
COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Clear DTC from PCM memory using WDS or
equivalent.
• Start engine.
• Is same DTC present?
9 VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
(See F2–86 AFTER REPAIR
• Is there any DTC present?
End Of Sie
F2–136
ON-BOARD DIAGNOSTIC
INSPECTION
INSPECTION)
INSPECTION)
PROCEDURE)
Yes Perform repair or diagnosis according to available Service
Information.
• If vehicle is not repaired, go to next step.
No Go to next step.
Yes Go to DTC P0200 inspection.
(See F2–129 DTC P0200)
No Go to next step.
Yes Repair or replace suspected fuel line, go to Step 8.
No Go to next step.
Yes Replace fuel injector, go to Step 8.
(See F2–55 FUEL INJECTOR
No Go to next step.
Yes Replace CKP sensor, go to Step 8.
(See F2–81 CRANKSHAFT POSITION (CKP) SENSOR
REMOVAL/INSTALLATION)
No Go to next step.
Yes Replace CMP sensor, go to Step 8.
(See F2–80 CAMSHAFT POSITION (CMP) SENSOR
REMOVAL/INSTALLATION)
No Go to next step.
Yes Implement engine overhaul for repairs, go to next step.
No Go to next step.
Yes Replace PCM, go to next step.
(See F2–64 PCM REMOVAL/INSTALLATION)
No Go to next step.
Yes Go to applicable DTC inspection.
(See F2–87 DTC TABLE)
No Troubleshooting completed.
A6E407001082228
ACTION
REMOVAL/INSTALLATION)