P0301 means your engine's computer has detected repeated misfires specifically in cylinder 1. Unlike P0300 which flags random misfires across multiple cylinders, this code points to a localised problem with that cylinder's spark plug, ignition coil, fuel injector, or compression, making targeted diagnosis more straightforward.
DTC/P0301·BMW
P0301 on BMW: Causes, Symptoms and Fix Cost
Quick Answer
High SeverityNot safe to driveBMW
P0301 on a BMW means your engine's computer has detected repeated misfires specifically in cylinder 1. Unlike P0300 which flags random misfires across multiple cylinders, this code points to a localised problem with that cylinder's spark plug, ignition coil, fuel injector, or compression, making targeted diagnosis more straightforward.
Repair cost on BMW€49 - €2380
What does P0301 mean on a BMW?
BMW 3 Series
2006-2024The N54 and N55 engines are notorious for ignition coil failures. Cylinder 1 is at the front of the engine and is most exposed to heat soak, leading to earlier coil failure. BMW recommends replacing all six coils and plugs at 80,000 km.
What causes P0301 on a BMW?
Beyond the generic causes listed on the main P0301 page, these are the BMW-specific patterns we see most often:
BMW 3 SeriesIgnition coil failure due to heat soak on N54/N55
BMW 3 SeriesCarbon buildup on intake valves (N54 direct injection)
How to diagnose P0301 on a BMW with OBD2
Follow these steps to pinpoint the root cause of P0301:
- Read freeze-frame data to check RPM, load, and coolant temperature at the time of the misfire
- Swap the ignition coil from cylinder 1 with another cylinder and clear codes. If the misfire follows the coil, replace it
- Remove and inspect the spark plug on cylinder 1 for wear, carbon fouling, or oil deposits. Replace if worn or gap is out of spec
- Use a stethoscope or noid light to confirm the fuel injector on cylinder 1 is clicking and receiving signal
- Perform a compression test on cylinder 1 and compare to adjacent cylinders. A difference greater than 10% indicates an internal engine issue
How much does P0301 cost to fix on a BMW? (EUR)
Estimated repair costs on a BMW (BMW parts and labour typically run 40% above the average for this code).
Prices estimated as of May 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0301 on BMW
These codes commonly cluster with P0301 on BMW vehicles:
FAQ: P0301 on BMW
What does P0301 mean on my car?
P0301 means your engine control unit has detected that cylinder 1 is not firing correctly. Each combustion event in that cylinder is monitored via crankshaft speed variations, and when enough misfires are counted, the code is stored.
Can a bad spark plug cause P0301?
Yes. A worn, fouled, or incorrectly gapped spark plug is the single most common cause of a single-cylinder misfire code. Replacing the spark plug on cylinder 1 is the first and cheapest step to try.
How do I find cylinder 1 on my engine?
Cylinder numbering varies by manufacturer. On most inline-4 engines, cylinder 1 is at the timing belt or chain end. On V-engines, check your owner's manual as it may be on either bank. The firing order label on the engine cover can also help.
Can I drive with a P0301 code?
It is not recommended. Continued misfires send unburned fuel into the catalytic converter, which can overheat and fail. If the check engine light is flashing, stop driving immediately to prevent expensive converter damage.
Why does P0301 appear alongside P0300?
P0300 logs when misfires are detected across multiple cylinders. If cylinder 1 misfires frequently enough, P0301 is also set. Fix cylinder 1 first, clear codes, and see if P0300 returns. It may have been triggered by cylinder 1 alone.
Looking for the full P0301 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0301 guideSkanyx · BMW
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