10-26-2012, 07:25 AM
Join Date: May 2008
My Ride: 2003 330Ci
| I believe the M52 series engines in the E46 used the MS42 ECU.
The M54B30 switched to the MS45 ECU around 03/2003 production. Before that it used the MS43 ECU.
There are differences in the O2 sensors, intake manifold is plugged at the air temp sensor for MS45 and MAF and other parts (SAP) between the MS43 and MS45 ECUs.
The MS45 ECU M54s will have a different Secondary air pump system that you can see in the engine compartment.
It includes a second Mass Air Flow sensor.
The trans swap threads here should answer any ECU/Trans electronic issues with the swap: I searched here using advanced search on Titles only for Auto Manual.
Discounts on new and CPO cars.
Most Dealers offer a parts discount, BMP Design 10% off
Last edited by shanneba; 10-26-2012 at 07:29 AM.