Random/Multiple Cylinder Misfire Detected
2012-2015 BMW 320i 2.0L I4 Turbo N20
Description
The PCM has detected misfires occurring in multiple cylinders randomly. This is different from a single-cylinder misfire and often points to a system-wide issue.
Symptoms
- Check Engine Light (flashing if severe)
- Rough idle
- Vibration
- Loss of power
- Hesitation
- Poor fuel economy
- Possible catalyst damage
Common Causes
- Vacuum leak
- Low fuel pressure
- Faulty spark plugs (all)
- Ignition coil pack failure
- EGR valve stuck open
- Low compression (multiple cylinders)
- Wiring harness issue
- MAF sensor problem
Diagnostic Steps
- Check for vacuum leaks (smoke test)
- Test fuel pressure
- Inspect spark plugs
- Test ignition coils
- Check fuel injectors
- Test compression
- Check MAF sensor
- Monitor fuel trim values
Repair Notes
Start with spark plugs and vacuum leaks. Flashing CEL means severe misfire - stop driving to protect catalytic converter.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P0300 on Other Vehicles
Common Questions
What does code P0300 mean on a 2012-2015 BMW 320i?
P0300 stands for "Random/Multiple Cylinder Misfire Detected". The PCM has detected misfires occurring in multiple cylinders randomly. This is different from a single-cylinder misfire and often points to a system-wide issue.
What are the symptoms of P0300 on a BMW 320i?
Common symptoms of P0300 include: Check Engine Light (flashing if severe), Rough idle, Vibration, Loss of power, Hesitation, Poor fuel economy, Possible catalyst damage.
What causes P0300 on a 2012-2015 BMW 320i?
Common causes of P0300 include: Vacuum leak, Low fuel pressure, Faulty spark plugs (all), Ignition coil pack failure, EGR valve stuck open, Low compression (multiple cylinders), Wiring harness issue, MAF sensor problem.