Battery going flat
- Thread starter Clw
- Start date
Welcome to the forum. 
It might be worth editing the header to your thread to something like "Wanted GM5 module for 2004 E85" as there are a few people on here who break Z4s from time to time, and depending where you are may be able to help you replace it.
It might be worth editing the header to your thread to something like "Wanted GM5 module for 2004 E85" as there are a few people on here who break Z4s from time to time, and depending where you are may be able to help you replace it.
Welcome aboard.Clw said:
Why do you think the GM5 needs replacing? What are the symptoms?
You can remove it and send it off to a company that will repair it for around £45. If it is a 'Star12 Low' version it will cost a little more.
It is also possible to swap in another one. The only differences will be if yours has had any extra coding done, but that can be sorted on a replacement one anyway.
May be worth getting hold of a second-hand one first and seeing if it fixes the problem.
Whereabouts are you?
A few people like me dotted around who could help you out by providing and fitting a replacement module.
That is a very good point as you don't mention anything about your battery? Be very odd for the GM5 to be flattening that?Mr Tidy said:Welcome to the forum.
It might be worth editing the header to your thread to something like "Wanted GM5 module for 2004 E85" as there are a few people on here who break Z4s from time to time, and depending where you are may be able to help you replace it.
Nice one mr tidy I haven’t got a clue how to post anything at the moment I have just joined . I m from Cardiff . The problem I have is this gm5 module is drawing the battery the bloke said after testing it . First of all the alarm kept going off in the night then the battery was going flat after a week of not driving. I’m pulling my hair out mate . Thanks for the reply
Lifer is a 'rank'. Not my name but never mind.Clw said:
The alarm going off could well be the bonnet switch, at the back of the engine bay between the two brace bar mounts. Try disconnecting that and see if it makes any difference.
For the battery drain check there are no lights left on. A favourite is the one inside the centre storage behind the seats. If the lug on the door snaps off it doesn't operate the micro-switch to turn the light off.
Also bear in mind that the cigarette lighter is permanently live. it doesn't switch off after 15 minutes like more modern cars do. So don't leave anything plugged in to that.
But even if it is the GM5 you should only be looking at about £50 outlay to either swap it or get yours repaired.
Luckily for you, [ref]umfaan[/ref] is not far away from you. He has shed loads of spares and could probably help slave in another GM5 to see if that cures it.
I have been chasing the cause of a battery drain issue on my E85 and looks like GM5, sending it off in the morning for repair, a bit fiddly but not so bad to get out and several online fixers for around the £50 mark. When I get it back and fitted back on I will update.
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.
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.
