Max time allowed for battery disconnection?

[Chris_D]

As per the title, I'm wondering what the absolute maximum timeframe is before transport mode kicks in on disconnection of the battery?
I understand it's something like 30 mins (?)

I'm planning to replace a faulty xenon ballast, so it's a bumper off job and a faff around taking the headlight unit out.
While I'm at it I thought I would refurb the headlights as they are shockingly cloudy. So it will be quite a few hours all told.

Naturally I'll be disconnecting the battery for the ballast removal as I don't really want to get zapped by high voltage and as I usually go slow and steady and get easily distracted the total job duration will probably take a couple of days.

Hence, do I need to keep an eye on the battery disconnection duration to avoid transport mode?

 

[Ewazix]

I might be repeating urban myth, but I understood that transport mode is SUPPOSED to be removed at the dealership before the new car is handed to the customer, but some slipped through (or dealers CBA?). I've certainly had my battery off for far longer than than 30 mins e.g. for several hours when things like a window regulator was being fixed and airbags were disabled.

 

[oldgitdave]

I disconnected my battery & removed the seats to fit heating & a leather refurb. It was disconnected for nearly 2 weeks, the only problem I had was the airbag light came on as I did have to briefly reconnect the battery to move the car without the seats in. I believe the transport mode should be deleted before sale, sure I've read it on here somewhere.

 

[Jl-c]

Is transport mode not a result of battery going low? AFAIK you should be able to disconnect then reconnect when done ie 12V or 0V so should be OK. I have had mine off for a day before.

 

[lucasxdiniz]

You can do all of that without removing the bumper or disconnecting the battery. I removed the projectors through the wheel well, and depending on the kit you buy to refurb the headlights, you can reach all of the frontal area as long as you have some masking tape on the bodywork.

But removing the bumper is dead easy or so I was told. Good luck!

 

[Ag51bye]

Can’t help On the duration, however can confirm transport mode kicked in on mine when left flat for a week or so.

Took it to a few places that couldn’t clear it before having to take it to BMW :headbang:

 

[Sail]

From my experience of working with BMW, transport mode should be disabled during PDI before it is finally handed over to the customer at the dealership.

Can’t help On the duration, however can confirm transport mode kicked in on mine when left flat for a week or so.

Took it to a few places that couldn’t clear it before having to take it to BMW :headbang:

May I ask what sort of symptoms you were experiencing? And did disabling transport mode fix your issues? It would be good to know what happens to the E85 Z4 in transport mode as I never came across one of these during my time at BMW. I'd assume it to be very similar to the E89 and G29 models I worked on...

Thanks

 

[Ag51bye]

From my experience of working with BMW, transport mode should be disabled during PDI before it is finally handed over to the customer at the dealership.

Can’t help On the duration, however can confirm transport mode kicked in on mine when left flat for a week or so.

Took it to a few places that couldn’t clear it before having to take it to BMW :headbang:

May I ask what sort of symptoms you were experiencing? And did disabling transport mode fix your issues? It would be good to know what happens to the E85 Z4 in transport mode as I never came across one of these during my time at BMW. I'd assume it to be very similar to the E89 and G29 models I worked on...

Thanks

Heater blower not working.
A/c button, heated rear window and many others on the heater panel not illuminating or working.

Possibly more but that was all i was aware of on my E86.

 

[MACK]

This comes up regularly on this and other BMW forums. My cars had its battery off for a day or so without issue. Transport mode should have been deleted as already mentioned as part of the cars PDI when it was sold. However it was much quicker just to turn it off/reset it so main dealers mechanics who were either lazy or stupid took the easy option. Hence why it plagues some cars and not others. It your car still has it any BMW specialist etc with dealer level software can delete it for you.