Heated mirrors and heated rear screen

[stevo8375]

Hi guys,

I’ve got a 2013 polo and the heated mirrors and heated rear screen don’t work, both fuses for them are ok. The heated rear screen switch doesn’t illuminate. Any ideas? Thanks in advance

Do both function through the same circuit?

[Maarten]

Do you hear a relay click when you push the rear window defrost button, or when you turn the knob for the mirrors?

[stevo8375]

No relay click, I’ve tried to find info on relays but can’t see any online to tell you which one it would be. My car only seems to have about 5 relays in the board

[iichel]

No they are independent circuits. The heated rear window relay is integrated in the BCM. It's not a separate relay.

[stevo8375]

Thanks for the info, how can I fix it? Any ideas…is it a software issue then do you think? Thanks in advance

[iichel]

Check for errors in the bcm please with a diagnostic scanner.

[Maarten]

No they are independent circuits. The heated rear window relay is integrated in the BCM. It's not a separate relay.

Of course, but he should hear a click when turning them on.

[stevo8375]

Thank you @iichel I’ll see if I can find someone local with vagcom

[stevo8375]

Are the heated mirrors controlled by the bcm also?

I’ve checked the fuse and it’s fine,
Switch seems to function fine (even tried a second switch to no avail). The movement of both mirrors work fine also

[amer6R]

hmmm maybe try removing the fuse and clean the metal prongs of the fuse

[stevo8375]

I’ve changed the fuse for new, no change

Also can anyone recommend a capable diagnostic tool, vcds stuff seems so expensive

[Maarten]

OBD11 probably.

You could test if the mirror heating wires get power.
Remove the glass and messure at the 2 wires that connect to the glass back.
If 0v they get no power, when you do messure current, the heating element could simply be broken.
Replace the glass and try again. (glass and heating element are useally already glued together.

[stevo8375]

I did change the passenger side mirror lens due to damage a few weeks back but it’s still the same, when I had the old glass out I did use a voltmeter and check it but it’s was showing 0v at the wires

[Maarten]

Then remains what iichel said, scan the BCM for errors

[stevo8375]

Appreciate it guys

Will obd eleven go into enough detail to read the bcm?