how to fix P0301 code in GMC Sierra T1XX (2019-Present)

Learn how to diagnose and fix P0301 cylinder 1 misfire in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shock.
• Ensure the engine is cool before starting work.

2. Inspect and Replace Spark Plug

• Remove the engine cover (if applicable).
• Locate the spark plug for cylinder 1 (usually at the front of the engine).
• Use a spark plug socket and ratchet to remove the spark plug.
• Inspect the spark plug for wear or fouling; replace it if necessary.
• Install the new spark plug, ensuring a torque specification of 13 lb-ft (17.6 Nm).
• Reinstall the engine cover.

3. Check and Replace Ignition Coil

• Disconnect the electrical connector from the ignition coil on cylinder 1.
• Remove the mounting bolts securing the ignition coil.
• Replace the ignition coil with a new unit, ensuring it's seated properly.
• Reconnect the electrical connector.

4. Inspect and Replace Fuel Injector

• Remove the intake manifold if necessary to access the fuel injector.
• Disconnect the electrical connector from the fuel injector.
• Use a fuel line disconnect tool to remove the fuel line.
• Remove the fuel injector retaining clip and pull out the injector.
• Install the new fuel injector and ensure a proper seal.
• Reconnect the fuel line and electrical connector.

5. Test and Clear Codes

• Reconnect the negative battery terminal.
• Start the engine and let it idle to check for any misfires.
• Use the OBD-II scanner to clear the P0301 code and monitor for any recurrence.