Comfort access issue

[MotoWPK]

Over the past 3 or 4 times I've driven my '13 128i cab, I observed that comfort access will not unlock when I touch the driver's door handle. It will unlock using the key fob button. I then observe upon starting the engine the "inspection light"; a car on a lift.

After turning off the car and locking it (using comfort access), it will unlock and start without the inspection light when done within a short time after shutting off and locking. It appears the issue arises when more than 10 or 20 minutes have passed after shutting off, which seems to me a time period corresponding to when all of the electronics are actually turned off.

Reading up on the what the footwell module (FRM) interfaces with, I note the list includes the driver's door locks and central locking and am wondering if the symptoms I'm seeing may be related to a failing footwell (FRM) module?

Thoughts?

[Shortedaman]

Originally Posted by MotoWPK

Over the past 3 or 4 times I've driven my '13 128i cab, I observed that comfort access will not unlock when I touch the driver's door handle. It will unlock using the key fob button. I then observe upon starting the engine the "inspection light"; a car on a lift.

After turning off the car and locking it (using comfort access), it will unlock and start without the inspection light when done within a short time after shutting off and locking. It appears the issue arises when more than 10 or 20 minutes have passed after shutting off, which seems to me a time period corresponding to when all of the electronics are actually turned off.

Reading up on the what the footwell module (FRM) interfaces with, I note the list includes the driver's door locks and central locking and am wondering if the symptoms I'm seeing may be related to a failing footwell (FRM) module?

Thoughts?

first thing to check is your battery before you jump to other conclusions. comfort access is like the first thing to act up when a battery is low or dying.

[MotoWPK]

Originally Posted by Shortedaman

first thing to check is your battery before you jump to other conclusions. comfort access is like the first thing to act up when a battery is low or dying.

Thanks for the suggestion, Shortedaman, the car is still on it's original battery, approaching 7 years in service.

But, shouldn't I see a warning in the instrument cluster if the battery is growing weak?

[blue135]

The warnings come from other than the instrument panel. As I think has been mentioned, BMW uses the ages old concept of "load shedding" when full battery power is not available. It starts cutting off power to accessories least essential to starting and running like comfort access and escalates to bypassing other non-essential systems as the battery continues to weaken.
Not unique to BMW. I can direct you to Chevy/GMC trucks that lose power to windows, security systems, etc. And suddenly all comes back to normal when battery alone is replaced.

[MotoWPK]

Thanks for that additional info blue135.

I did check the static voltage this morning and it measured at 12.34V, which is low and, from experience, indicates to me the battery is probably nearing its end of life - not surprising after almost 7 years in service (and actually a bit more than 7 years since vehicle manufacture).

[ferocity02]

7 years is a long time for a SLA battery, that's roughly what I got on my original battery in my 07 335i. It's time to replace it.