Fault code

P0301 fault code.

This code comes up with one known fault.

Generic code

Code type

Engine and drivetrain

System

Misfire on cylinder 1

The engine control unit detects a misfire from the momentary slowdown of the crankshaft, and tied this one to cylinder 1. An ignition coil, a spark plug, an injector or a leak can all cause it. The repair is often a new spark plug or a new ignition coil.

The code tells you what the control unit measured, not which part has failed. The same code has several possible causes.

Which known faults it comes up with

TSI ignition coil: misfire, jerking, engine warning light

cheap repair

The per cylinder ignition coil of these direct injection, turbocharged petrol engines fails. According to the Haynes service material this and similar simple electrical faults account for roughly eighty per cent of workshop visits.

Show the rest

In cold, damp weather, on startup, the engine runs unevenly, misfires under acceleration, and the engine warning light flashes or stays on. Do not keep driving with the light flashing: the unburnt fuel destroys the catalytic converter.

What to check

Start with a cold engine and watch the first half minute: a rough idle or shaking is suspect
On the test drive load the engine at low revs with a lot of throttle: the misfire shows then
A flashing engine warning light calls for stopping immediately

2 more steps in the write-up

Information, not an expert opinion

We write the descriptions, and we put the source next to them. A person reviews them before they go out. They are still information, not a technical expert opinion.

A fault on the list does not mean the car you are looking at has it.
A fault missing from the list does not mean the model is fault-free. Write-ups are made model by model. Not all of them are done.
You decide whether to buy. This is no substitute for an inspection. That needs a workshop and a history check.

Details in the terms