my BMW 3 Series E90/E91 (2005-2012) is skipping gears, what should I do?

Solution

1. Preparation

• Gather tools and parts needed.
• Disconnect the battery to prevent electrical shorts.
• Raise the vehicle securely using jack stands.

2. Check and Replace Transmission Fluid

• Sub-steps:
  1. Locate the transmission fluid dipstick (if applicable) or fill plug.
  2. Remove the dipstick or fill plug and check fluid level; add fluid if low.
  3. If the fluid is dark or smells burnt, proceed to drain and replace.
  4. Drain old transmission fluid through the drain plug into a suitable container.
  5. Replace the drain plug with a new gasket and torque to manufacturer specifications.
  6. Refill the transmission with the recommended type and amount of fluid through the dipstick or fill plug.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Fluid pump (for refilling transmission fluid)
• Drain pan

3. Inspect and Replace Transmission Components

• Sub-steps:
  1. Remove any covers or shields obstructing access to the transmission.
  2. Inspect the transmission linkage and cables for wear or damage; replace if necessary.
  3. If testing solenoids revealed faults, disconnect the wiring harness and unbolt the faulty solenoid.
  4. Replace with a new solenoid and reconnect the harness.
  5. Reassemble all components and covers securely.

4. Test Drive

• Sub-steps:
  1. Reconnect the battery.
  2. Start the engine and allow it to reach operating temperature.
  3. Conduct a test drive to evaluate the transmission performance and verify that the skipping gears issue has been resolved.