P0302 code definition
No fire detected on cylinder 2
What code P0302 means
Most vehicles have 4 or 6 cylinders. Each cylinder fires one spark plug after another. There is a spark plug at the top of each cylinder. The spark plug uses an electric spark to ignite the flammable fuel-air mixture, producing energy.
The energy released by burning the fuel drives the crankshaft. All the cylinders work together to regulate the rotation of the crankshaft. During the combustion of each cylinder, the crankshaft is allowed to rotate continuously. It is this process that ensures the smooth operation of the vehicle.
The crankshaft revolutions per minute (RPM) can increase or decrease if one of the cylinders fails. If the percentage of this increase or decrease is greater than 2%, the powertrain control module will register a fault code.
If the crankshaft rpm increases or decreases by 2 to 10 percent, the Check Engine light will come on. If the crankshaft rpm increases or decreases more than 10 percent, the Check Engine light will come on. A flashing Check Engine light indicates a more serious misfire problem. Error code P0302 indicates that there is an ignition interruption in cylinder 2 and the spark plug is not receiving the proper spark.
What causes the P0302 code?
- Faulty spark plug in cylinder 2
- No compression on cylinder 2
- Faulty or worn spark plug wires and/or coils.
- Damaged or worn distributor cap (not applicable to all vehicles).
- Rotor knob damaged or worn (not applicable to all vehicles).
- Defective fuel injectors
- Blocked valves or EGR lines
- Burnt valves
- Inaccurate ignition timing
- Vacuum leaks
- Low fuel level or low fuel pressure
- Cylinder head gasket leakage
- Defective distributor cap
- Camshaft sensor defective
- Crankshaft sensor defective
- Air mass sensor faulty
- Defective oxygen sensor
- Defective throttle position sensor
- Defective catalytic converter
- Traction unit control module defective
What are the symptoms of the P0302 code?
- Check engine light comes on or blinks
- The car won’t start or is difficult to start
- Car fights to speed up
- Engine runs weak or idles
- The car has no power while driving
- Parking lots or stops while stopped
- Increased fuel consumption
How can a mechanic diagnose a P0302 code?
- Uses an OBD-II scanner to collect frozen frame data and fault codes stored by the powertrain control module.
- Check if fault code P0302 reappears while driving the car.
- Check cylinder 2 spark plug wire for worn or damaged wires.
- Check cylinder 2 spark plug for wear or damage.
- Check for worn or damaged coil wires.
- Check the coils for excessive wear or damage.
- If necessary, replace damaged spark plugs, spark plug wires, coils, and coil wiring.
- If fault code P0302 returns after replacing the damaged spark plugs, coil packs, spark plug wires, and coil pack wiring, check the fuel injectors and fuel injector wiring for damage.
- For vehicles with a distributor cap and rotor button system (older vehicles), check the distributor cap and rotor button for corrosion, cracks, excessive wear, or other damage.
- Diagnose and repair any other related trouble codes recorded by the powertrain control module. Perform another test drive and see if trouble code P0302 reappears.
- If trouble code P0302 reappears, inspect the cylinder 2 compression system (this is not a common occurrence).
- If trouble code P0302 remains unresolved, it may indicate a problem with the powertrain control module (not common). It may need to be replaced or reprogrammed.
The most common errors when diagnosing the P0302 code.
Before replacing spark plugs, coil packs, or cables with spark plugs and coil packs, visually inspect the fuel injector cables for damage. If applicable, diagnose and repair any other related trouble codes that are present. Also rule out a defective cylinder as the cause of the problem.
Any of these components can cause trouble code P0302. It is important to rule out all possible causes of the ignition error code during diagnosis. Addressing them during this process will save a lot of time.
How serious is the P0302 code?
The error code P0302 is considered serious. Some of the symptoms of this code make the vehicle unsafe to operate. The vehicle may stop abruptly or stall. Also, if the error code is not cleared, other engine components may be damaged. For these reasons, the P0302 fault code requires immediate attention.
What repairs can fix a P0302 code?
- Replacement of faulty or defective spark plugs.
- Replacement of defective spark plug wires
- Replacement of damaged coil wires
- Replace clogged EGR valves or clogged EGR lines
- Replace burnt out valves
- Repair vacuum leaks
- Repair or replace leaking cylinder head gaskets
- Replacement of camshaft sensor if defective
- Replace crankshaft sensor if it is damaged
- Replace mass airflow sensor if damaged
- Replace oxygen sensor if damaged
- Replace throttle position sensor if damaged
- Replace fuel injectors if damaged
- Replace catalytic converter if damaged
- Diagnose and repair any associated fault codes stored by the powertrain control module.
- Replacement of the distributor cap and rotor button, if damaged and applicable to the vehicle
- Repair of damaged internal engine components.
- Replace the engine if the cylinders are damaged.
- In rare cases, the powertrain control module may need to be replaced or reprogrammed.
Additional notes on code P0302
When one of the spark plugs needs to be replaced, the other spark plugs must also be replaced. When one of the spark plugs needs to be replaced, it is not necessary to replace the other spark plugs. This type of code is usually an indication that the car needs maintenance, so replacing a spark plug does not usually solve the problem.
To quickly determine if the cause of the fire problem is a faulty wire or coil pack, replace the wires or coil pack from cylinder 2 with wires or coil packs from another cylinder. If the generator set control module registers an error code for that cylinder, it means that the wire or coil pack is the cause of the misfire. If there are other error codes related to the misfire problem, these must also be diagnosed and repaired.
Make sure that the spark plugs are properly seated. Use a spacer to ensure accurate spacing of the spark plugs. Inaccurate spark plug spacing will cause another ignition error. Spark plugs should be grooved according to the manufacturer’s specifications. These specifications are usually found on a sticker under the hood of the vehicle. Otherwise, these specifications can be obtained at any local auto parts store.
