Any ideas how to check/fix this fault?

[benjie]

Hi guys, had this fault code pop up - it says intermittent and don't I know it - some days no rear vision, others, it's fine!

Anyway, here's what VAG-COM threw out...


"Address 08: Auto HVAC Labels: 8E0-820-043.lbl
Part No: 8E0 820 043 H
Component: A4 Klimaautomat 1116
Coding: 00000
Shop #: WSC 63351

1 Fault Found:
00975 - Heated Rear Window (Z1)
31-10 - Open or Short to Ground - Intermittent"

Does anybody have any ideas on what wiring to check (and where it is?!) Haven't owned this car long, so not overly familiar with it!

Any thoughts welcome!

[Marco34]

Have a look here for some fault codes as a starting point. Must admit I've never seen those before...

http://wiki.ross-tech.com/index.php/Category:Fault_Codes

[benjie]

Yeah, I checked there before I posted up, it's not there. It's got to be witing though, I just wondered where the wires to the back window run really. I'll have to investigate a bit more!

[philpugh]

Sounds like faulty connection somewhere. My Bora has three of the 'elements' of the rear heated window not working - but I don't get any codes thrown. You should be able to find the connectors from the rear window quite easily - they will be close to the screen edge. I seem to recall they are spade connectors. Probably worth giving these a good cleaning. Only other things would be dodgy switch or just possibly the fuse/relay.

[benjie]

OK, cheers, am getting a haynes manual at the weekend so will have a go then!

[benjie]

Update...
Can anybody help? The fault wording has changed. It now reads

Address 08: Auto HVAC Labels: 8E0-820-043.lbl
Part No: 8E0 820 043 H
Component: A4 Klimaautomat 1116
Coding: 00000
Shop #: WSC 63351

1 Fault Found:
00975 - Heated Rear Window (Z1)
36-10 Output won't Switch or Short to Plus - Intermittent.

Nothing seems to have changed though, it still doesn't really work.
What doesn "Output won't Switch" or "Short to Plus" mean? And does anybody know how to fix this?

Any ideas will be gratefully received!

[martin1810]

Use a multimeter or just a test lead to check the switch has 12v going to it and coming out of it when you switch it. Then test the wire where it connects to the screen. This will tell you roughly where the fault is. i.e. Before the switch, the switch, or between switch and screen.

[benjie]

Thanks for that!
I'll have a check.

[bearthebruce]

1 Fault Found:
00975 - Heated Rear Window (Z1)
36-10 Output won't Switch or Short to Plus - Intermittent.

Nothing seems to have changed though, it still doesn't really work.
What doesn "Output won't Switch" or "Short to Plus" mean? And does anybody know how to fix this?

Any ideas will be gratefully received!

Short to Plus means just that - the output is stuck at 12 volts. The controller can not switch the output between ground (On) and Battery voltage (off). It remains stuck at battery voltage. It's got to be a wiring problem somewhere or possibly a fault in the window heater.