X4 Gearbox Issue

[UpsideDown]

I own a 2017 30d X4 with 59K miles & have an odd issue with the gearbox.

Every now & again when stop/start is engaged the gearbox will drop out of Drive into Neutral & the engine will restart. Not sure why this would be the case but assume it issue is electrical rather than mechanical as there are no other issues with the gearbox as it still changes gear as normal.

I have tried to google a possible root cause but found nothing meaningful, so any ideas would be appreciated.

[E30M3SE]

How old is the battery?

If stop/start is engaged and the electrical draw is excessive or prolonged car will restart and select Neutral so as not to leave you stranded in traffic with a car that won't start.

[danb79]

UpsideDown said:

I own a 2017 30d X4 with 59K miles & have an odd issue with the gearbox.

Every now & again when stop/start is engaged the gearbox will drop out of Drive into Neutral & the engine will restart. Not sure why this would be the case but assume it issue is electrical rather than mechanical as there are no other issues with the gearbox as it still changes gear as normal.

I have tried to google a possible root cause but found nothing meaningful, so any ideas would be appreciated.

As above

An old battery, failing or failed; can cause all sorts of weird and wonderful issues

Get it tested if you can to see what its health is

Or if you have a multimeter; check it yourself. Voltages need to be c12.4v engine off / car asleep & c14.4v with the engine running

[UpsideDown]

The battery is still the original one so is likely to be the issue so will check it out. Thanks.