2003 3.0i E53 - Crank no start problem w/ a twist

[tjm1943]

2003 BMW X5 3.0i w/ 180k



After a lot of searching on the forum for somebody that has experienced anything similar to what I am battling right now and not having any luck I decided I just need to post. I was also looking for some sort of DME/TCM box diagram that shows/describes what modules are for what. Sorry if I missed something in my search. Also my first post so sorry if i leave out critical information.


Basically, my X5 was parked for the summer (6 months). I had the chance to drive something more fun and jumped at the chance. It was garage stored and hooked up to a battery charger during this time. I managed to go start/run it a couple times in the first couple months but not in the last 4 months (probably mistake #1). Went to start it back up recently and it cranked but would not start/run. Keeps cranking but just wont quite start. Tried jumping it and still wouldn't start. I checked the plugs and they were BAD. Replaced those and still cranks but wont run. Started checking fuses (both in the back compartment and glovebox) but didn't find any blown fuses. Plugged in the code reader but its not showing any codes. We did a spark test. Made sure there is fuel @ the rail. Just cant figure out why it wont run. Then I stumbled upon the fuse/relay box in the engine compartment..


So a mouse had made my DME/TCM box its home for the summer. Lots of chewed wires but nothing appeared to be chewed through. Taped up all the wires nicely so nothing is exposed now. Checked the fuses in the remote fuse box and they were good. Tried to start it again and it still cranks but wont start.


Next step is going to be checking the voltage to the relays and modules in that fuse box. Or should I just throw my hands up now and walk away? I've never had a rodent problem in a vehicle and the one time i do, its probably the worst possible vehicle. Other things i thought about are the fuel filter and MAF sensor?



I also don't know what all the modules and relays in that box are for. Any information on that or suggestions on what to do would be awesome! I've used this forum to troubleshoot some previous issues and found this site super helpful so I'm hoping somebody can point me in the right direction



Thanks!