how to troubleshoot P0302 code on Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, socket set, torque wrench, compression tester, vacuum gauge, and basic hand tools.
• Ensure the vehicle is parked on a level surface, and the engine is cool to touch.
• Disconnect the negative battery terminal to prevent any electrical shorts.

2. Inspect and Replace Spark Plugs

• Remove the ignition coil cover (if applicable) to access spark plugs.
• Using a socket wrench, carefully remove the spark plug from cylinder 2.
• Inspect the spark plug for wear (such as carbon buildup or damage).
• If replacement is needed, install a new spark plug with the correct gap setting (typically around 0.044 inches for the Corolla).
• Torque the spark plug to the manufacturer’s specification (usually around 13 ft-lbs).

3. Test and Replace Ignition Coil

• Disconnect the ignition coil connector and remove the coil from cylinder 2.
• Use a multimeter to test the primary and secondary resistance of the ignition coil according to service specifications.
• If the coil is faulty, install a new ignition coil and reconnect the wiring.

4. Inspect and Test Fuel Injector

• Remove the fuel injector connector and the retaining clips to access the injector on cylinder 2.
• Check the injector for clogs using a fuel injector cleaning kit or swap it with another injector to see if the misfire moves.
• If the injector is defective, replace it with a new one and ensure proper installation.

5. Compression Test

• Remove the spark plug from cylinder 2 and connect the compression tester.
• Crank the engine several times and note the compression reading; compare it to the manufacturer's specifications (typically around 180-200 psi).
• If compression is low, further investigation into the valve seals or piston rings may be needed.

6. Reassemble and Reconnect Battery

• Once all components are inspected and replaced as necessary, reinstall any removed parts in the reverse order.
• Reconnect the negative battery terminal and ensure everything is secured.