P0302
Worn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable), Incorrect ignition timing, Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor, Defective Crankshaft and or Camshaft Sensor, Defective Throttle Position Sensor, Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems).
- Audi
- Powertrain
- Generic code
- High severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 3
- AreaIgnition system or misfire
- 02
- FaultThe specific fault in that area
What it means
P0302 means the engine control unit has detected misfiring on cylinder 2. It sets when crankshaft speed monitoring shows that cylinder is not contributing its share of power, either intermittently or constantly. On an Audi the cause is most often ignition related, but fuel, air and mechanical faults can also set it.
Symptoms
- Rough or uneven idle
- Engine shudders or hesitates under acceleration
- Flashing or constant engine warning light
- Loss of power and poor throttle response
- Smell of unburnt fuel from the exhaust
- Increased fuel consumption
Possible causes
- Worn or faulty spark plug on cylinder 2likely
- Failed or weak ignition coil on cylinder 2likely
- Faulty or leaking fuel injector on cylinder 2possible
- Vacuum or intake leak near cylinder 2 (hose, manifold seal or gasket)possible
- Low or weak fuel pressure, or a fault with a sensor such as the air mass, crankshaft or camshaft sensorpossible
- Mechanical problem on cylinder 2 such as low compression, a leaking head gasket or valve damagerare
How to diagnose
- Read all stored codes and freeze frame data to see load, rpm and temperature when the misfire set, and check for other related codes
- Check the live misfire counters to confirm the misfire is only on cylinder 2
- Inspect the coil connector, wiring and the spark plug for damage, wear, oil or fouling
- Swap the cylinder 2 coil with another cylinder, clear the codes, retest and see whether the misfire follows the coil
- If the misfire stays, swap or test the spark plug and then check the injector operation and wiring on cylinder 2
- Inspect intake hoses and seals for leaks, and check fuel pressure and fuel trim data
- Carry out a compression test or leak-down test on cylinder 2 if ignition and fuel are ruled out
- Check the model and engine specific service information, as coil, plug and injector types vary
How to fix
- Replace the spark plugs as a set to the correct specification
- Replace the faulty ignition coil
- Replace or professionally clean and test a faulty injector
- Repair the vacuum or intake leak and replace damaged seals or hoses
- Correct fuel supply or sensor faults found during testing
- Carry out the necessary engine mechanical repair if compression is low
Can I keep driving?
Avoid driving if the warning light is flashing, as unburnt fuel can damage the catalytic converter. If the light is steady and the engine runs reasonably, drive gently and short distances only until it is fixed.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.
This code for other makes
Nearby codes
- P0301AudiWorn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable), Incorrect ignition timing, Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor, Defective Crankshaft and or Camshaft Sensor, Defective Throttle Position Sensor, Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems)
- P0303AudiWorn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable), Incorrect ignition timing, Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor, Defective Crankshaft and or Camshaft Sensor, Defective Throttle Position Sensor, Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems)