Parasitic Battery Drain e53

[upallnight]

Originally Posted by itscoo2pyopants

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%

Sounds like problem with an unloader relay.

[HotWheelsRedline]

Originally Posted by itscoo2pyopants

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.)

[Overboost]

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.

[HotWheelsRedline]

Originally Posted by Overboost

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.

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.

[Overboost]

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...

[Fifty150hs]

Originally Posted by Overboost

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.

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.

[upallnight]

Originally Posted by HotWheelsRedline

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.)

Just remember "A happy Wife makes for a happy Life".

[g300d]

I'm in the same boat with my 04 3.0i.

I thought I'd licked my drain issue when I removed the fuse powering the audio amp (had a speaker humming with radio off).

But this morning after 4 days the X wouldnt start.

Read through the entire thread and learned a lot from everyone's posts. I hope to have enough time to begin troubleshooting soon.

I did peek inside if the window lock and shifter lights shut off and they did, so it looks like the X is going to sleep.

[Crowz]

Well I just removed the tcu from mine. Charging the battery up now for testing.

If it isn't down any tomorrow problem solved hopefully.

If I wasn't going to switch to an aftermarket radio anyway I would permanently fix the tcu issue by rewiring its power feed to an ignition wire in place of live all the time.

Come to think of it I may do that anyway. Kind of sounds like fun and it will be a bit before the new radio gets here anyways.

Well lets see how this test goes first.

[HotWheelsRedline]

Thanks for all the replies. Good to know the e53 doesn't need the battery programmed. This is a more common problem than I realized. I'll report back once my indy figures it out.