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Old 11-15-2012, 04:45 PM   #12
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Join Date: May 2008
Location: Indiana
Posts: 2,182
My Ride: 2003 330Ci
2003 models built up to 02/2003 still used the MS43 ECU (My car was built in 02/2003)
Starting with production in March 2003 the ECU changed to the MS45 (also the "performance package' was introduced)

VIN NUMBER: WBABS53463EV90482 - Built 2002-12-09

Your original car should have had a MS43 ECU, only those built from 03/2003 on have the MS45.

You could use your old harness, changing the O2 sensors from the old engine to the newer one.
You would also have to at least remove the Intake Air temp sensor out of the old engine intake manifold, remove the plug in the new engine's intake manifold and install the sensor.
Maybe more.....

For wiring diagrams check here:
BMW wiring diagrams -
Discounts on new and CPO cars.
Most Dealers offer a parts discount, BMP Design 10% off

Last edited by shanneba; 11-15-2012 at 04:47 PM.
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