Battery Drain
DTC IS 2DED, POWER MANAGEMENT code in dme
Battery drain is 210 milliamps after 2 hours, with picoscope and amp clamp
around battery cable. Customer says battery goes dead after 3 days.
looking for an efficient method, based on personal experience.
Tommorrow morning I will thermal image the car, and volt drop the fuses etc etc
Anything else to look out for?
…Be sure to keep a charger on it all night and trip all latches and use the thermal imager first thing in the morning on all components and wire bundles/relays /motors/ switches/alternator act. … Dan H.
Yes. I'd suggest to perform an energy diagnosis if you haven't done one already. I'd also be checking to see if the bus was active or off with a scope.
Obviously one of the modules isn't going into sleep mode. Do a complete scan of all modules, if you haven't done so and that should tell you which module is being effected and then after sitting overnight scope each buss circuits to see which one is staying awake. Had to do this on a Porsche to find the drain. Probably won't have a code in the effected module.
Does the vehicle have comfort access? Where you grab the door handle and it unlocks automatically? If so disconnect the sensors to the door handles and see if the vehicle goes to sleep and your draw goes away. -That is a typical issue for draw concerns with no faults.
Agree with all of the above Darren but also ask the owner for a list of what is not working/not working correctly/intermittently on the vehicle, no matter how trivial it may seem. On about 90% of battery drains, once you find them the customer will say “oh yea, that hasn't been working right for a few weeks now” Also bad for water leaks in the boot area where there are multiple modules low…
Another tip to lead you “down the Road” is take your amp clamp and go to each large red cable and see what your readings are. if one larger supply wire has a larger draw see what that cable provides power to and branch off from there. Also the customer get the battery drain message on the heads up display with the time and date incorrect? if so be mindful of a faulty IBS
E60 usually ccc unit has fan on rear , if you have factory tool you can do an energy diagnosis
210 milliamperes is low enough where I do not believe it is a sleep mode prevented ( bus staying active situation. I believe you might have an individual consumer staying on. It was mentioned that the battery in the trunk has at least 3 red power cables coming off the positive post. One should be going to the front of the vehicle jump start terminal feeding starter and alternator. Another feeds…
Referencing Jose' Alcantars' suggestion of isolating the power draw to one of three sources, may I suggest that the Alternator may have diode leakage that is causing the current to be converted into small amounts of heat. I've seen it before on the same model of car. It just takes a second to verify and may end your search. Hope this helps.
Energy diagnosis should help. Any decent European scan tool has the ability to perform this….
There was a video here on the DN showing how to do a parasitic drain test on a BMW using the fuses during a voltage drop testing. Search out the video. Very informative and may help you a lot. I'd post a link, but I can't anything I search for here on the DN.
I know its our friends from over the “pond” giving this seminar and it can be a lil harder to follow but its good! youtube.com/watch?v=z3WTHD…