Heated seat problem

[ostanton]

I have a strange problem that I will contact the dealership about but it is always useful to hear if anybody has had a similar problem. Very occasionally the seat will start to heat on its own without me pressing the control button to activate this function. Is there an automatic function that turns on the seat heater? I am unable to find such a function in the manual. I suspect a malfunction but would be interested to hear other opinion. 2004 645Ci. Magnificent car!

[pan]

Although I don't have a passenger in the car frequently it is fairly often my wife has complained the passenger seat feels hot. It may have been turning on on its own. I have only noticed a warm driver's seat once or twice but could not definitely say it was actually on.

[cobradav]

There is no automatic on except in the sense that if you turn it on, then shut down car and return and start up prior to the car having gone into sleep mode your "heater on" setting is retained. Except for that no automatic and absolutely no reason for it to come on. I have miss hit the passenger heater on once or twice in trying to force PDC off or on. They are next to each other and no real differentiation by feel except the seat heater switch is the outermost switch (Drv or Pas sides) for seats.
_______
US '05 645 Coupe|Silver Grey|Chateau|Sport|Logic 7|HUD|Cold Pkg|SAT|AUX|BT w/ snap-in adapter|MP3|V1|CIP 25.02


www.bimmerdrivers.com

[ostanton]

Thanks cobradav and PAN. The dealer today gave a somewhat plausible explanation (after finding everything OK) in saying that my black leather seats in Californian sun will absorb heat only to give it back when I sat on the seat. Air conditioning would cool me off except for my back which would temporarily feel hotter until the heat equilibrated. We all need a workable narrative even if it isn't true and the dealer in this sense was immensely helpful!!

[pan]

If I am not mistaken every switch in the 650 is a software switch which means it only takes a software bug to engage the seat heater. It has happened often enough when my wife is in the seat with a noticable warmth to the seat (greater than the ability to warm with a tush) to possibly have concern the seat heater is on.

[cobradav]

Do the lights on the switch come on when this happens?
_______
US '05 645 Coupe|Silver Grey|Chateau|Sport|Logic 7|HUD|Cold Pkg|SAT|AUX|BT w/ snap-in adapter|MP3|V1|CIP 25.02


www.bimmerdrivers.com

[pan]

No lights come on. This is why I could never be sure it was residual sun heat or the seat heater actually came on.