BMW E36 ECU removal and installation
  - How to remove and replace the ECU (Engine Control Unit) in your E36


In our case, we were replacing a stock ECU with one modified with a modified ROM. In most cases, the actual ROM Chip will have to be installed by the end user, however, we were lucky enough to obtain a pre-modded ECU.

Elton

DANGER

Any information presented or implied is for entertainment purposes only. A car and related parts can be very dangerous to work around. Please exercise extreme caution when performing any kind of repair or modification. Neither I or any affiliated parties can be held responsible for any problems or accidents which may occur.

Prepare the necessary items. You only really need two tools here: A phillips head and flathead screwdriver. Locate the battery.

Disconnect the (-) ground terminal from the battery. Locate the firewall cover in the upper left corner (passenger side) of the engine bay.

Remove the upper three plastic clips with a flat head screwdriver. Optional: remove the 2 lower fastners with a socket

Locate the three screws on the plastic cover. Use a phillips head screwdriver to remove the three screws.

This is what it looks like with the cover removed. Pull the metal tab on the ecu connector to disconnect the wiring harness.

Remove the 2 phillips head screws on either side that hold the ecu down. With the screws removed, slide the ECU out.

Do what you need to do with your ECU.
Installation is an exact reversal of the removal steps.