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

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, fuel injector cleaner.
• Safety Warnings: Disconnect the battery before starting any electrical work. Allow the engine to cool before touching engine components.

2. Inspect and Replace Spark Plug

1. Remove the engine cover if applicable.
2. Using a socket set, remove the spark plug from cylinder 3.
3. Inspect the spark plug for signs of wear, such as carbon buildup or electrode erosion.
4. If necessary, replace the spark plug with a new one that meets OEM specifications.
5. Torque the new spark plug to the manufacturer's specifications (typically around 13-15 lb-ft).

3. Check and Replace Ignition Coil

1. Disconnect the electrical connector from the ignition coil on cylinder 3.
2. Remove the ignition coil using a socket set.
3. Inspect the ignition coil for any signs of damage or corrosion.
4. If faulty, replace the ignition coil with a new one that meets OEM specifications.
5. Reinstall the ignition coil and reconnect the electrical connector, ensuring a secure fit.

4. Inspect and Clean Fuel Injector

1. Disconnect the fuel injector connector for cylinder 3.
2. Remove the fuel injector using the appropriate tool (may require special injector puller).
3. Inspect the injector nozzle for clogs or dirt.
4. Clean the injector with a fuel injector cleaner or replace it if defective.
5. Reinstall the fuel injector, ensuring it is seated properly and reconnect the electrical connector.

5. Perform Compression Test

1. Remove the spark plug from cylinder 3.
2. Install the compression tester into the spark plug hole.
3. Crank the engine and record the compression reading.
4. Compare the reading with the manufacturer's specifications; if low, it may indicate internal engine issues.