Applicable for most vintage cars, including BMW (e24, e28, e30, etc) and more.

The best, but a bit unnecessary, method is:

  1. Reset the ECU by:
    1. Disconnect battery terminals
    2. Attempt to start the vehicle
    3. Depress brake pedal (with battery disconnected) 10 times
    4. Reconnect power
  2. Start vehicle and idle until fully up to operating temperature
  3. Shut off, reset the ECU once again
  4. Restart, allow vehicle to idle for 5 minutes
  5. Drive normally for 30 minutes
    • most vehicle do not apply any new fuel corrections above about 3/4 engine load and 3/4 max-rpm, therefore normal driving is best driving

The absolute minimum method to reset learning is:

  1. Reset the ECU by:
    1. Disconnect battery terminals
    2. Attempt to start the vehicle
    3. Depress brake pedal (with battery disconnected) 10 times
    4. Reconnect power
  2. Drive away