how to fix P0302 code in GMC Sierra T1XX (2019-Present)?

Learn how to diagnose and fix P0302 cylinder 2 misfire in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts for the repair.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench
• Remove the engine cover (if applicable) using a socket set.
• Locate the spark plug for cylinder 2.
• Use a spark plug socket to remove the old spark plug.
• Inspect the spark plug for wear; replace if necessary.
• Install the new spark plug by hand to avoid cross-threading, then torque to manufacturer specifications (usually around 13 lb-ft).

3. Inspect and Replace Ignition Coil (if needed)

• Disconnect the electrical connector from the ignition coil.
• Remove the mounting bolts using a socket set.
• Carefully pull out the ignition coil from the cylinder head.
• Install the new ignition coil by reversing the removal steps; ensure it’s seated properly and reconnect the electrical connector.

4. Check Fuel Injector

• Disconnect the fuel injector connector for cylinder 2.
• Using a noid light, verify that the injector is receiving a signal.
• If no signal is detected, trace and repair wiring or connections as needed.
• If the injector is faulty, remove it and replace it with a new one, ensuring proper O-ring placement and connection.

5. Clear Codes and Test

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0302 code.
• Start the engine and conduct a test drive to confirm the repair.