Current Drain

[Silverstar]

Recently I have noticed if I leave my car standing for more than a couple of days I get a message on the drive screen and dashboard saying something about excessive battery drain. Once I went back to the car after it was left standing for 3 days and on the fourth day the battery was completely dead, not a sign of life in the car at all, meaning I had the to charge the battery overnight to get it working again.

I have some aftermarket accessories plugged in which I thought might be the culprit, such as sound system dash cam etc. so I unplugged each of these but it made no difference. Checking each day with a multimeter I can see the battery draining more and more every day.

I installed a new Varta battery less than 2 years ago and registered it to the car. To rule out a defective battery I have had it tested to make sure it is not defective which it isn't so yesterday my mechanic put it on his scanner but the only error popping up is a defect in the electric heated door mirrors. I don't know if this is causing the problem and on the other hand I have never been able to test the heated mirrors since well it never gets that cold here to need them.

Anyone had a similar experience or have any ideas before I spend money taking it to an auto electrician?

 

[B21]

Excess battery drain is often caused by the DME failing to close down all but essential cicuits..usually because another device, Bluetooth, Comfort Access etc is faulty or has a s/w related issue..

I have it on my 35is where Comfort Access is preventing full shut down, looks like a faulty comfort access fault..

Using ISTA / Protool you would usually see a DME error and most likely an error from the module causing the issue..

 

[Silverstar]

Probably the scan tool that my mechanic has cannot pick up the fault although I wonder if it is related to the heated mirror defect it did pick up.

Is Protool still android only? I don't have ISTA either which I am guessing is Windows only. I guess the best bet is to take it to the local BMW dealers for them to give me diagnostic readout.

 

[jamesgarbett]

I've had a similar problem for some time now. Never got as bad as the car failing to start though. When I can remember i do put the battery on a CTEK

 

[B21]

Probably the scan tool that my mechanic has cannot pick up the fault although I wonder if it is related to the heated mirror defect it did pick up.

Is Protool still android only? I don't have ISTA either which I am guessing is Windows only. I guess the best bet is to take it to the local BMW dealers for them to give me diagnostic readout.

Hi yes ISTA is windows only and the install and use is not very user friendly…

Bimmergeeks Protool is Android only..I’m an Apple user but just bought a cheap ruggedised Chinese android phone as a dedicated Protool device..just like you might do with a cheap code reader like Foxwell..

 

[Smartbear]

When you leave the car for a few days is it locked? If the car’s left unlocked it causes it to stay “awake” for hours before it shuts down properly.
Rob

 

[Silverstar]

When you leave the car for a few days is it locked? If the car’s left unlocked it causes it to stay “awake” for hours before it shuts down properly.
Rob

Yes I always lock it.

 

[Silverstar]

Probably the scan tool that my mechanic has cannot pick up the fault although I wonder if it is related to the heated mirror defect it did pick up.

Is Protool still android only? I don't have ISTA either which I am guessing is Windows only. I guess the best bet is to take it to the local BMW dealers for them to give me diagnostic readout.

Hi yes ISTA is windows only and the install and use is not very user friendly…

Bimmergeeks Protool is Android only..I’m an Apple user but just bought a cheap ruggedised Chinese android phone as a dedicated Protool device..just like you might do with a cheap code reader like Foxwell..

Will have to consider doing this, thanks.

 

[Silverstar]

A quick update. Took my car in to my local BMW specialist who hooked it up to their diagnostics. They found that there was no communication with the audio module and suggested as B21 said that it was not shutting down and hence draining the battery.

They reckon it’s the MMi box that is connected to the radio that is causing the fault! Means I am now going to have to disconnect the MMI box and put the car’s original loom back in the radio to check.

 

[B21]

A quick update. Took my car in to my local BMW specialist who hooked it up to their diagnostics. They found that there was no communication with the audio module and suggested as B21 said that it was not shutting down and hence draining the battery.

They reckon it’s the MMi box that is connected to the radio that is causing the fault! Means I am now going to have to disconnect the MMI box and put the car’s original loom back in the radio to check.

Hmm interesting..keep us posted