how to fix P0303 code in Ram 1500 DT (2019-Present)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Ram 1500 DT. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery to prevent electrical shock.
• Allow the engine to cool down before proceeding.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil from cylinder 3 by unscrewing the bolts and disconnecting the electrical connector.
• Using a spark plug socket, remove the old spark plug from cylinder 3.
• Inspect the old spark plug for signs of damage or excessive wear.
• Install the new spark plug, ensuring it is torqued to the manufacturer’s specifications (typically around 13-15 ft-lbs).
• Reattach the ignition coil, ensuring the electrical connector is securely fastened.

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil using a multimeter for resistance.
• If the coil is faulty, disconnect it and replace it with a new one.
• Reconnect the electrical connector and ensure it is secure.

4. Clean or Replace Fuel Injector

• Tools Required: Fuel injector cleaner or replacement injector, fuel line removal tool
• If the fuel injector is clogged, remove it from cylinder 3 using the fuel line removal tool.
• Clean the injector with a specialized cleaner or replace it with a new injector.
• Reinstall the injector, ensuring all connections are tight.

5. Conduct Compression Test

• Tools Required: Compression gauge
• Connect the compression gauge to the spark plug hole for cylinder 3.
• Crank the engine and record the compression reading.
• If compression is below manufacturer specifications, further investigation into internal engine components may be necessary.