how to fix P0302 code on BMW X3 F25 (2011-2018)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, fuel injector testing tool, vacuum gauge.
• Disconnect the negative terminal of the battery to prevent electrical shorts.

2. Inspect and Replace Ignition Components

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector for cylinder 2.
  3. Remove the ignition coil using a socket set.
  4. Inspect the spark plug for cylinder 2; if damaged or fouled, replace it.
  5. Install a new ignition coil (if necessary) and reconnect the electrical connector.
  6. Torque the ignition coil to the manufacturer's specification (typically around 15-20 Nm).

3. Test and Replace Fuel Injector

• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder 2.
  2. Remove the fuel injector using the appropriate tool.
  3. Test the fuel injector's resistance with a multimeter (specification is usually around 12-16 Ohms).
  4. If the injector is faulty, replace it with a new one.
  5. Reinstall the fuel injector and reconnect the electrical connector.

4. Perform Compression Test

• Sub-steps:
  1. Remove the spark plug from cylinder 2.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine for several seconds and record the compression reading.
  4. Compare the reading with the manufacturer’s specifications (typically around 120-180 psi).
  5. If compression is low, further investigation into valve or piston issues may be required.