OBD-II DTC · POWERTRAIN · Severity: HIGH
P0300: Random/Multiple Cylinder Misfire Detected
Crankshaft position sensor angular velocity fluctuations indicate combustion misfires across two or more cylinders.
| DTC Code | P0300 |
|---|---|
| Standard Definition | Random/Multiple Cylinder Misfire Detected |
| Subsystem | POWERTRAIN |
| Urgency / Severity | HIGH |
| Standard Reference | SAE J2012 / ISO 15031-6 |
1. Symptoms
- Flashing or steady Check Engine Light
- Engine vibration and loss of power
- Risk of rapid catalytic converter overheating
2. Common Root Causes
- Worn spark plugs or failing ignition coils
- Vacuum leak or EGR valve stuck open
- Low fuel pressure or contaminated fuel
- Timing chain/belt stretch or low compression
3. Diagnostic Procedure
- Do not drive under heavy load if MIL is flashing
- Check Mode $06 misfire counters per cylinder
- Inspect spark plugs, coil boots, fuel pressure, and intake vacuum integrity