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Old 12-14-2018, 08:43 PM
Fifty150hs Fifty150hs is offline
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Quote:
Originally Posted by whizzkid23 View Post
Well, it seems that the day has come for our 2005 x5 3.0i to start draining the battery because of a somehow faulty TCU unit. The bluetooth module (Fuse 74) seems to keep waking up the car from sleep mode every 10/15 minutes or so, drawing a 0.5Ampere for a few minutes. Result = dead battery after a night or two in cold days.

Long story short: Besides this power drain, the bluetooth module is working great and I love the quality of the microphone and everything else. I really would like to keep it in working condition.

The solution that came to my mind is to power the TCU trough a power source that is directly bond to the ignition switch position. Logic: Key turned = TCU powered, Key removed = TCU without power.

I could cut the original power supply to fuse 74 and steal the power from the rear lights, but I guess the LCM would notice a too high power drain. Maybe some of you have a smarter idea or approach on how to power this unit (obviously always securing the circuit with the proper fuse).
The usual fix is to simply pull the fuse for a day or so then plug it back in. For whatever reason that seems to usually remedy the problem.
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