Xoutpost.com - Parasitic Battery Drain e53

Xoutpost.com (https://xoutpost.com/forums.php)

- X5 (E53) Forum (https://xoutpost.com/bmw-sav-forums/x5-e53-forum/)

- - Parasitic Battery Drain e53 (https://xoutpost.com/bmw-sav-forums/x5-e53-forum/106762-parasitic-battery-drain-e53.html)

Quote:

Originally Posted by itscoo2pyopants (Post 1114387)

My dads 2000 x5 has been having a battery drain also. We changed batteries, alternator, changed the Headunit, disconnected various components / pulled fuses trying to figure out where the draw was coming from. Dealership had it for 2 weeks and charged 700 for diagnosing saying it was the instrument cluster. Replaced that. Still killing the battery. Finally took it to a private guy that does independent diagnosing for dealerships in the area. He had it for a 4 hours and was able to get it fixed:

"Memory wire" on the head unit
Rear defrost
Headlight switch
And rear drivers side tail light

all drawing a current when the vehicle was "asleep". Not sure exactly what he did to fix the issues because his explaination was very technical. But my advice is to find someone that specializes in electrical. Not all dealers / Indies are able to handle these issues without throwing money at it. The last guy charged $400 and it was fixed 100%

Re-reading this, it sounds like you've been down the same road I have -- replacing the battery, alternator and getting a diagnosis that the instrument cluster is to blame, but you replaced it and that didn't fix the problem. So, now I'm skeptical of my cluster diagnosis! Fortunately, I've only spent $115 on the diagnostic (then of course $450 for the alternator), but AAA refunded my battery cost. I just don't want to get into a money pit with this, replacing things willy-nilly. And my wife is ready to jettison the car, since it's her daily driver!

After being "asleep" in the garage for a few hours, I went out to check and the red light by the gear shift was back on, then turned off seconds later as I stood there. So something is waking the car back up randomly....

(And thanks "Overboost," but I'm not messing with the soldering/electronics myself.)

Unplug fuse 74 in the back or your cargo area. This is for the TCU. This is what was waking my system up and killing my battery. Do you have any devices like Dice or anything tapped into the K Bus? My TCU went bad and pulling fuse 74 solved my drain. Replaced the TCU and all good again.

Possibly a dumb question, but isn't the cluster just a bunch of gauges? Could the cluster awaken the car/system by itself? Also, somebody mentioned "uploader relay" -- where do I look into that?

Quote:

Originally Posted by Overboost (Post 1115420)

two different BMW techies ran multi-meter tests and other diagnostics and found: "Faults for CAN communication to instrument cluster in both the engine and transmission computers. Noted the temp gauge in the cluster came on by itself and swept several times before turning back off. Recommend replacing inst. cluster based on these faults and observations.".

and no add-on devices.

You might just try it, for a couple of days. You will only lose bluetooth if you are using it. CAN bus errors can trigger just because of traffic on the bus. Mine had the same errors with the bad TCU. Temp gauge I have no idea other than it could have been the diagnostic tests they were doing... :dunno:

Quote:

Originally Posted by Overboost (Post 1115420)

I had the same problem. Turns out the TCU is a common problem. I disconnected my TCU since I wasn't using it anyway. Haven't had a parasitic drain problem since.

Oh seeing the can bus errors that was something else my tcu was causing besides just killing the battery all on its own.

After removing it I have no errors and the battery doesn't die.

Of course as I imagine most noticed that ran across my radio install thread I removed the factory radio now so now I don't have the tcu, factory nav disc unit or cd changer draining power either :)

Quote:

Originally Posted by Overboost (Post 1115424)

Just checked -- there is no fuse in slot 74....

Quote:

Originally Posted by HotWheelsRedline (Post 1115503)

Just checked -- there is no fuse in slot 74....

Pull the fuse for your NAV. That's another common culprit as is the FSR.

Quote:

Originally Posted by Fifty150hs (Post 1115505)

Pull the fuse for your NAV. That's another common culprit as is the FSR.

Yup, I've gone thru all the common culprits (NAV, radio, FSU, etc.), as have two BMW techs with diagnostic equipment. That's what led to the instrument cluster diagnosis, but no guarantees it will solve the problem either.