Removal & Installation (3-Series)

ECU is located behind cover on firewall in right rear of engine compartment. On 4-cylinder vehicles, remove battery. On all vehicles, remove 4 ECU cover screws. See Fig 1. Unlock electrical connector retainer. Disconnect electrical connector. Slide out ECU. See Fig 2. To install, reverse removal procedure.

Fig 1: Removing ECU Cover Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: Removing ECU

Courtesy of BMW OF NORTH AMERICA, INC.