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Curious about the outcome as well. Experienced this once when i was on vacation for 14 days. normally i drive the car every single day so not a huge issue for me

Redgum, not sure if this will be useful to you but I did a draw test today and think I have found the problem. With all the fuses on, the car was draining around 0.75-1.0amps. This is after removing fuse 26 to stop the light inside boot from being lit and doors closed. When fuse 50 was removed, reading dropped to 0.25-0.35 amps.

Based on the Z4 fuse diagram from another webpage, fuse 50 is for Radio Amplifier and it seems right as audio player is not working without the fuse. To add, audio player stopped working immediately after a battery replacement in 2021 and turning on randomly a couple of times on its own for few minutes. Current battery drain problem started after the audio player turned on and continued to work since this April. So, based on this and draw test, I think audio player is to be blamed here. I will continue to monitor the battery voltage for few more days and if it stays good, I need to move on to fixing the audio player.

My Z does not have an amplifier so that isn't the case but now the GM5 module has been removed I have a 10milliamp drain, hopefully this will be repaired and the issue resolved. As for my radio, it went into disable mode after removing a battery and can't find any info to fix, this radio does not need a code.

If the radio is dead what about the Aircon and heated rear screen? If these are also dead your car is in transport mode low battery condition will set this to close the systems down to conserve what power is left for starting. If it is in transport mode you need a scanner capable of resetting it to Normal, doing so restores the systems to working. Be aware not all scanners can reset this.BMW scanner 1.4 on a laptop can reset it but not delete it to avoid this happening again. High end tablet scanners like Launch and Autel can delete it permanently, they remove transport mode from all theodules that have it in one operation, something that the selling dealer/stealer should have done when doing the PDI on the car, probably foresaw £££'s as sooner or later owners would end up with transport mode and have no clue as to what's going on.Radio in Z4 doesn't need a code unless it's been fitted with an aftermarket radio.

Interested to see how this all pans out.

colb wrote: ↑Thu Aug 10, 2023 2:46 pm If the radio is dead what about the Aircon and heated rear screen? If these are also dead your car is in transport mode low battery condition will set this to close the systems down to conserve what power is left for starting. If it is in transport mode you need a scanner capable of resetting it to Normal, doing so restores the systems to working. Be aware not all scanners can reset this.BMW scanner 1.4 on a laptop can reset it but not delete it to avoid this happening again. High end tablet scanners like Launch and Autel can delete it permanently, they remove transport mode from all theodules that have it in one operation, something that the selling dealer/stealer should have done when doing the PDI on the car, probably foresaw £££'s as sooner or later owners would end up with transport mode and have no clue as to what's going on.Radio in Z4 doesn't need a code unless it's been fitted with an aftermarket radio.

Yes Aircon and heated rear screen are also not functioning. I suspect the car might have gone into transport mode. Thinking to get a BMW scanner 1.4 and check this myself.

I will see if the heated rear screen and air con work this weekend, just waiting for the GM5 to arrive back and accorded to the company that fixes them it had several faults, hopefully the battery drain and central locking may work.

I've had a battery drain problem on my 2006 E85 for a while now. I always put it down to the car sitting for a while (it's used regularly but not every day). Had a few garages have a look but nobody able to get to the bottom of it and no power in garage so not easy to put car on trickle charge. Anyway just came across this video saying that battery drain could be due to the light being permanently on in the centre console due to a the plastic tab on the door which operates the microswitch being broken. Thought there's no way that can be whats happening to my car as never noticed a light coming from centre console area when car switched off. Went to have a closer look, door seals quite well so it's difficult to see at first but sure enough the light was on and the tab that should operate the microswitch is broken off . Fixed for now by unplugging the light (never use that area) rather than using the fix shown the video. Might be worth checking this on your car if you are experiencing battery drain issues https://youtu.be/pvQcQS8Rgig?si=XvjwwThin_ksLuK5

Thanks for that but had my GM5 module repaired and double wammy, no drain on battery plus have full central locking now.

That's great to hear. thanks for the info! Definitely sending mine in to get repaired in the coming months. During the summer the car is fine but in the winter, it does some suspicious things

Hi black bee sorry for the late reply. The problem with my battery going flat was a faulty boot catch . It ment that the boot light stayed on some times . All sorted now .