Fix heated mirror - code 00920

[furfurfur]

My driver's side heated mirror doesn't work - I actually had to reach out and rub the ice off, like some sort of animal! Never really noticed the heated mirrors in the old C6 until it doesn't work...

VCDS says:

00920 - Heated Outside Mirrors; Driver Side (Z4) / Passenger Side (Z5)
012 - Electrical Fault in Circuit
Freeze Frame:
Fault Status: 01101100
Fault Priority: 3
Fault Frequency: 18
Reset counter: 225

So, looks like it's been like this for a while.

Where to start looking for this? It's not a very helpful fault code

[gupsterg]

I think you've got this car recently? (reading some of your past posts)

Mine at purchase had stick-on glass replaced on one side and the heating wiring had been unpluged from mirror ... as weather was warm I only noticed as one side would dim but not the other ... I promptly replaced this with a genuine one from ebay ...

[furfurfur]

Yup, had it a couple of weeks and just working my way through the very small amount of niggles.

Just been reading the service manual - does the glass really just pop out as easy as all that? Looks like a 2 minute job

[gupsterg]

Yep, done it a few times now... I used a wedge (one for laminate flooring) wrapped with duct tape...

Attachment 18789

I found moving mirror up slightly allowed more room to use wedge... then down to do top section... as you can see in guide clips are only in centre...

[furfurfur]

OK, I whipped it out for a visual inspection...

There seem to be more connectors than I was expecting, see attached picture. Could this be for an auto-dimming function of some sort? I know my interior mirror auto-dims but not sure if this is linked to the exterior ones. Could mean quite a lot more money for the replacement part.

Also - I use my multimeter to test the resistance between the two element pins and there's nothing there - open circuit. So the element does seem to be knackered.

Any idea about the extra black connector?

[gupsterg]

Black connector is your auto dimming wiring... pink capped wiring is the heating element...

So if you checked the points where pink cap wiring go (which it sounds like) then yes heating element may have gone... it may be an idea to move mirror control knob to heated (the middle point) and check voltage out of the pink capped wiring... from what I understand even if mirror control on heated you need frost symbol by DIS temp to make function, but with VCDS there is a measuring block which can check the heating function IIRC...

I got mine from ebay for about £100 dealer IIRC £200+...