How to Replace a BMW 330I ECM Module

1. Remove the cable from the negative terminal of the battery with a socket wrench. This prevents anyone from starting the engine during the EBCM replacement procedure.
2. Remove the cover for the hydraulic control unit, or HCU, on the right side of the engine compartment. The HCU is a cube-shaped component with hydraulic brake lines connected to it. The EBCM is a smaller, narrow component on top of the HCU.
3. Release the clamp on the EBCM. Pull off the right side of the multiple plug from the EBCM, and disconnect the left side of the plug from the EBCM. Disconnect the mounting bolts from the EBCM with a socket wrench, and remove the EBCM from the vehicle.
4. Install the new EBCM to the HCU, and fasten the mounting bolts for the EBCM with a socket wrench. Connect both halves of the multiple plug to the EBCM.
5. Attach the clamp on the EBCM, and replace the cover for the HCU. Attach the cable for the negative battery terminal with a socket wrench.