Hi friends, I noticed that passenger side heated mirror is not functioning on my new to me 2006 525xi.I mean its not getting warm.Driver side works fine.I scanned it with ISTA and strange thing is that its not throwing any error code. Aren't heated mirrors electronically monitored by control module like bulbs??Any ideas please?Thanks

 

here's some info from the wiring diagram system.


Mirror functions
Functional description, see BMW Technology:

TIS -> Documents> SI Technology -> 61 10 03 (032)

Notes on function
The door mirrors are connected to the door modules. The mirror functions

•Mirror adjustment

•Mirror pivoting

are operated from the switch block in the driver's door:

The following options are also available:

•Electrochromic rear-view and door mirrors

•Mirror memory in conjunction with seat memory



Mirror heating

The mirror heating is active as of terminal 15 On and is controlled depending on the outside temperature and wiper intensity. When the wiper is running, the heat output is increased so as to ensure reliable deicing of the mirror glass.

The mirror heating is switched off under the following conditions:

•Terminal 50 active (load cutoff)

•On-board supply voltage under 10.8 V

•Activation of a memory position

In the case of vehicles with the option independent heating, the door mirrors are also heated during independent heater operation.
"

 

 

 

looks like there is a wire (pin 4 on the mirror connector) for the heater. perhaps it would be worth testing continuity on that wire in certain situations and comparing to the drivers side and seeing if you can pinpoint the issue.

i.e. from the BMW documents, it seems that the heater is turned on when the outside temperature reaches a certain point and the heat is increased when the wipers are on. i would check pin 4 on the drivers side and confirm that there is voltage/continuity during this situation to make sure you know the heater is on. if so, check pin 4 on passengers side. if nothing on passenger side, you may need to trace the wire backwards to the connector at the door and then back to the body gateway module behind the glove box. maybe there is a split or short somewhere. all mirror functionality looks to be controlled by one fuse so if your power mirrors are adjusting, it would appear not to be a general power issue.

 

Thanks Boston jon for the documents!! Will have a look this weekend.Wondering how come mirror heater is not monitored by the control module?

 

Update:
So i removed just the glass from the mirror assembly and found the heating circuit on the glass was open.I then removed the back plastic cover by heating it with hair dryer and prying it out carefully with plastic trim removing tools.After separating the back,i could clearly see the where the break was.Then i bridged the break by carefully removing the resin from the trace and soldering a wire straight on to the silver heating trace.But i am not confident about the solder joint between wire and silver trace.But i did try to wiggle the joint and it was still making good connection and was showing 7.2 ohms of resistance after soldering the bridge.I then assembled it back and it started heating.I compared both mirrors using laser contact less thermometer and they both were showing almost same temp of around 20 deg C when ambient temp was 2 deg C.Hopefully my solder joint would stay in place.If it breaks again,then i will just get a new glass.