how to fix P0305 misfire code on my Ram 1500 DT (2019-Present)

Learn how to diagnose and fix P0305 cylinder 5 misfire in Ram 1500 DT. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts: OBD-II scanner, spark plug socket, torque wrench, multimeter, compression tester, replacement spark plug, ignition coil (if needed), and possibly a fuel injector.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Disconnect the negative battery terminal.
  2. Remove the engine cover if necessary to access the spark plug.
  3. Use the spark plug socket to remove the spark plug from cylinder 5.
  4. Inspect the spark plug for wear; replace if damaged or fouled.
  5. Gap the new spark plug to the manufacturer's specifications.
  6. Install the new spark plug and torque to the recommended specification (typically 13-15 ft-lbs for most applications).

3. Inspect and Replace Ignition Coil

• Sub-steps:
  1. Disconnect the electrical connector from the ignition coil on cylinder 5.
  2. Remove the mounting bolts and carefully lift the ignition coil out.
  3. Visually inspect for damage or corrosion.
  4. If faulty, install a new ignition coil and secure it with bolts.
  5. Reconnect the electrical connector.

4. Test Fuel Injector

• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder 5.
  2. Use a multimeter to test the injector resistance; compare with specifications.
  3. If the injector is faulty, replace it with a new one.
  4. Reconnect the fuel injector connector.

5. Compression Test (if necessary)

• Sub-steps:
  1. Remove the spark plug from cylinder 5.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine for a few seconds and take a reading.
  4. Compare the reading with the manufacturer's specifications; if low, further investigation is needed.