DTC P0300: Notes
DTC P0300 DETECTION CONDITION AND POSSIBLE CAUSES
| DTC P0300 |
Random misfire detection |
| DETECTION CONDITION |
- PCM monitors CKP sensor input signal interval time. PCM calculates the change of the interval time for each cylinder. If the change of interval time exceeds the preprogrammed criteria, PCM detects a misfire in the corresponding cylinder. While the engine is running, PCM counts the number of misfires that occurred at 200 crankshaft revolutions and 1, 000 crankshaft revolutions
and calculates misfire ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, 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).
- MIL illuminates if PCM detects the misfire which affects emission performance in two consecutive drive cycles or in one drive cycle while DTC for the same malfunction has been stored in PCM.
- PENDING CODE is available if PCM detects the misfire which affects emission performance during first drive cycle.
- MIL flashes if PCM detects the misfire which can damage the catalytic converter during first drive cycle.
- FREEZE FRAME DATA is available.
- DTC is stored in the PCM memory.
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| POSSIBLE CAUSE |
- CKP sensor malfunction
- CMP sensor malfunction
- Ignition coil malfunction
- Ignition system malfunction
- MAF sensor contamination
- Excess air suction in intake air system (between MAF sensor and intake manifold)
- Fuel pump malfunction
- Fuel pressure regulator malfunction
- Clogged fuel line
- Clogged fuel filter
- Fuel leakage in fuel line
- Fuel run-out
- Poor quality fuel
- Purge control solenoid valve malfunction
- PCV valve malfunction
- EGR valve malfunction
- Vacuum hose damage or improper connection
- Related connector and terminal malfunction
- Related wiring harness malfunction
- Insufficient compression
- Variable valve timing control system improper
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