P0302 Cylinder 2 Misfire

Possible causes code P0302 Cylinder 2 Misfire

• ASD relay output.
• Injector control circuit.
• Coil control circuit.
• Ignition wire.
• Spark plug.
• Ignition coil.
• Fuel delivery system issue.
• Fuel injector.
• Engine mechanical.
• Powertrain Control Module (PCM).

Diagnose code P0302 Cylinder 2 Misfire

(Sorry!!! Step 1-2, refer to code P0301)
Step 1. Check for an active DTC

Step 2. Visual Inspection

Step 3. Ignition system operation

Turn the ignition off, remove the ignition coils. Connect the ignition coil harness connectors. Disconnect the fuel injector harness connector of the cylinder being tested. Install a spark tester on the ignition coil. While cranking the engine observe the spark coming from the spark tester.

Note: A crisp blue spark that is able to jump the gap of the spark tester should be generated at the coil on plug and the end of the ignition wire.

Is good spark present?

Yes, go to step 4.

No, go to step 13.

Note: Connect the fuel injector harness connector before continuing.

Step 4. Spark plug

Turn the ignition off, remove the spark plugs. Inspect the spark plugs for the following conditions:

• Cracks.
• Carbon tracking.
• Foreign material.
• Gap size out of specifications.
• Loose or broken electrode.

Note: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move.

Were any of the above conditions present?

Yes, replace the spark plug.

No, go to step 5.

Step 5. Fuel pressure check

The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.

Before continuing, visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary.

Install the decay tool to the fuel rail. Start the engine and observe the fuel pressure reading. Fuel pressure specification is 400kpa +/- 14kpa (58psi +/- 2psi).

Choose a conclusion that best matches your fuel pressure reading.

Within specification, go to step 6.

Below specification, go to step 11.

Above specification, replace the fuel pressure regulator.

(Sorry!!! Step 6-8, refer to code P0303)
Step 6. Fuel pressure leak down

Step 7. Fuel injector operation

Step 8. Engine mechanical

(Sorry!!! Step 9-11, refer to code P0304)

Step 9. Fuel injector control

Step 10. Injector control circuit

Step 11. Fuel supply line restricted

(Sorry!!! Step 12-14, refer to code P0305)

Step 12. Fuel pump inlet strainer

Step 13. ASD relay output circuit

Step 14. Ignition coil

(Sorry!!! Step 15-17, refer to code P0306)

Step 15. Coil control 2 circuit shorted to ground

Step 16. Coil control 2 circuit open

Step 17. Powertrain Control Module (PCM)

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