We had a accident in our first x5 and so we bought a second one with a blown engine and no battery we had the engine and battery swapped out but it will not start. Do we just need to get the battery coded or is that really a must thing? Also does the engine need coded we have heard that also? Please give advise we took to local BMW dealer but they just keep trying to get us to buy a new one and will not look at it. All advice is welcome as this is our only vehicle we are $3,000 plus into it and have been without a vehicle for 3 months. Thanks in advance please please help!!!

Morning Ashley

Welcome to the Forum

I take it the engine and Battery are from your accident damaged X5? Are the donor car and the receiving car same Model/Year? For example X5 4.4 2004/5 into a 2004/5 X5 4.4?

Who did the engine swap? Did they move the DME/DDE from the old car or are they the ones in the new car? 2004/5 models shouldn't need battery registration.

So assuming the donor and receiver are the same model/year have you checked the simple stuff like engine earth and all sensors connected? When the battery is connected are you getting lights on the dash? Basically the engine as a unit doesnt know where it is so providing the sensors are OK and connected correctly the DME/DDE can receive signals, so check all connections including engine earth and starter motor. 

Are the fuel pumps running ? check fuel delivery at the injectors?

You really need a BMW Specific Diagnostic Program to know what is going on.

Dave