My goodness...



Don't daily drive a Naughties BMW. Big Money Waster, indeed.



The car still won't crank, despite us now having spent another 5-6 hours trying everything we can think of to figure out why the DME is not communicating with the rest of the car. New news:

• I sent back my DME, VVT, EWS, and key back to ECU Pro and they confirmed that all the modules worked together on their test vehicle with zero errors.
• The battery had drooped again to 10.5V after 2 weeks of sitting with the key 598 miles away. Charged it up with a big 2-60A charger we used to use on race cars. Charged it at 2A for an hour and then 20A to get to 12.9V. During the charging process, we disconnected the car's battery terminals and touched them together to "clear the modules" or whatever witchcraft the forums have told me occurs.
• We took the case off the old DME so that we could access the pins at their board connections. We then went through the entire DME to measure resistance across the junctions between the car's wiring and the DME PCB to make sure corrosion wasn't the issue. All pins measured between 0.4Ω-0.7Ω.
• With the case off, we made sure the DME was seeing 12V on the board, which it seemed to.
• The car's OBC now randomly shows the tachometer at 5000rpm, the coolant temperature maxed out, and the oil temperature maxed out. It still says the transmission is in fault mode and that DSC and 4x4 are inop.
• The airbag light is NOT on, so unlikely a BST via the SRS system (I hope).
• Quick scan of the modules now shows 4-5 new errors through the KOMBI, all related to DME communication over CAN.

The only remaining thing I can think to do is to tow the car to a local BMW expert and hope they've seen something similar and know where to snoop. If they can't find anything, I'm literally debating trailering the car all the way up to PA and have ECU Pro look at it, themselves. They mentioned they had a car that took a similar sh*t before. However, it turned out to be a corroded contact issue, and we have sussed that out.



How do I confirm the function of the BST? I do still have three faults in the seat occupancy section of the scanner: an "SBBF Undervoltage" and two "SBBF Control-Unit Fault". Could this SOMEHOW be the issue? My dad and I figured it would be very obvious that the charge had popped and would remove all voltage to the DME. Is this not how it works? Is there like a "code" sent that just shuts down some of the communication to the rest of the modules while keeping the power pins at 12V?



Please, someone help me with this thing. This car is (well... was) my daily driver. This is the second BMW I've owned that has bricked with some mystery DME issue (the first being an E34 540i 6-speed that was turned in on Cash for Clunkers). This is, absolutely, the last Nazirocket I buy. It has ruined me on German cars. It is unbelievably good when it works... but ya know...