TheRedStig

So I've had little electrical issues for a long while but they're growing and I'm at a loss. I know very little about electrical DIY so I'm in need of serious help. I've taken it to my local indy. His made it clear that there was something drawing the voltage down. He said it was most likely water getting into the trunk and that a new seal would have me fixed up. I've replaced the seal and it has gotten worse.



Vital Stats
2008
E60
535i
150k
SA/Auto

Symptoms

Comfort access fails to work and when I unlock the car with the button and get in it has reset the clock. This seems to happen a few times a week.

Once a month at most the active steering will be disabled when starting the car. It will correct itself within 1/4 driving (Aside from one time that it stayed off from Nashville to Little Rock, this required a trip to the Indy to get mended)

All kinds of codes
Waterpump codes (Replaced that just to be safe, codes came right back)
2E8B Intelligent Battery sensor
2E7C serial data interface signal
2EA1 oil condition sensor
2E98 Generator communication
Fuel pump codes sometimes

and many more at times.

It should be noted that the Indy mentioned that the oil level sensors often go wrong and draw a lot of current so with my most recent oil change I swapped it with a brand new one. So it's not that.

I'm at a loss with what to do aside from take it to the Indy and let him pour through the car again...Any suggestions will be absolutely considered and probably acted on.. I just swapped the starter yesterday so I'm capable of a lot...I just need someone with knowledge to direct me a bit here.

ripley

How old it the battery and has its condition been checked?

TheRedStig

Great question. Should've put it in the op.

Yes twice. Once by pep boys about 4 months ago and once more by the Indy when he first diagnosed around 3 months ago.

I've gotten advice that this could still be the issue as things have gotten worse and may soon just spend the money to get a new one and see what happens.

maximum96

I just read on another forum of an e90 having alot of the same faults u mentioned, it ended up being a bad ground strap. I don't know where all locations of grounds r for the e60 though...

TheRedStig

I've been hoping it was this but can't find solid proof about where it is either. Sounds like it's attached to one of the motor mounts but I need to get under there to be sure...

dingolfing

Recently my rear passenger comfort access door handle started misbehaving and would constantly re-lock the car when it was parked. This of course will drain the battery and I would get the high battery drain message upon the next startup. When it became worse, the date and time would reset. So I disconnected that door handle and the problem went away.

You say comfort access fails to work. Is that just on one door? Try other doors first, if they work, then you've found the bad door.

Just a thought anyway. Our cars have so many electronics, your problem could be anything.

amesser325

You or your mechanic can chase which circuit is the offending draw by going circuit by circuit with an ammeter. As a first pass you can go fuse by fuse with the key off without the vehicle asleep (~16 min after last action - door open, etc). See where the big draw is - most will be ~0 or so. There will be few with 1+ amp draw, so you can then focus on them. You just need to revisit each higher draw circuit but now have to wait until the car goes to sleep. It's best to avoid connecting the meter in series because they generally don't have much amperage throughput (ie, you'll pop the fuse in the meter) but I'd guess your mech will already know that.

It could also be telling if there is not drop off from pre- to post- sleep voltage draw. That would indicate to me a module is not shutting down. At that point you should be able to look at a wiring diagram for that circuit to narrow down where to look. The ISTA/D tool does a good job of compiling that info together (including where to physically look in the car).

Regards,

Andy
07 530xiT 6MT

JuniorB

First thing you need to do is a load test on the battery. Drive the car for a while, disconnect the battery terminals and check voltage and do a load test,leave them off till the morning. Repeat the process,if it reads lower than a normal reading, change out the battery.

incoherent

Change out the battery.. I had the exact same problem. I took my battery out and had it deep cycle tested on the battery machine at my dealership. Passed the test..

Everyone insisted my battery was fine. I replaced it anyway and all of my issues went away instantly.

Just make sure you replace it with the exact same battery that's in the car otherwise you'll have to get it programmed.

JuniorB

This car is very complex and most just say to start replacing sensors. A battery can have good volts, but hold low amps. These cars are very smart and can detect the slightest drop,, so when a code is present, and a random one pops up, it's a good indication the battery is nearing it's full duty cycle. This happens so frequently and often overlooked. The heavy ground strap can also cause the same issue being exposed to the elements.