The only slight glitch is an intermittent Open or Short to Ground thrown up by a VCDS scan related to the seats but this does not seem to have any Function Limitations so I am not too concerned at the moment. I will see if I can latch onto what circumstances promote this and report back. I did check the resistance of the heating circuit in both seats prior to installation and they were exactly the same so that gave me some reassurance that all was in order.
@Lozzy15 Just a bit more on that error. It was B1339 14 [009] - Open or Short to Ground. By chance having looked around on the wonderweb I came acorss a thread on heated seats on the TT Forum where the poster had the exact same error and found that by changing the Value for ‘Seat heater level current consumption allocation-Sitzheitzubgsfreigabe’ to ‘Not Installed’ as opposed to ‘unvernetztes_Heizmodul_verbunden’ suggested in your guide the error could be cleared and did not reoccur.
I have done that and indeed it seems to work for me in and the installation in my car (Mk3 FR Facelift 2019) and with my second hand HVAC control (ie error cleared and not coming back).
Unrelated to this is that yesterday I realised that I had only ever used the heated seats with both me and a passenger in the car and both using the heated seats function. But then yesterday I was in the car by myself and had the drivers seat heating turned on except it wasn’y getting hot but the empty passenger seat was heating up nicely.
I have checked today with the Advanced Measuring Values and everything for both the heated seats is reversed left to right, ie the heating operation and also the temperature sensing. I followed the Kufatec wiring instructions (copy attached) and double checked prior to reassembling. [The reference to
Permanent positive at fuse spot SC45 relates to the power for the powered drivers seat.] I can believe I might have got one wrong wire/pin placement but it seems difficult to understand how I might have perfectly reversed all of them left to right. My suspicion is therefore falling on the Kuatec instruction sheet.
I will pass this by Kufatec after the weekend but whatever the cause, it needs correcting. However I am very reluctant to take out the BCM in order to swop over wires bearing in mind all the trim to be removed and the difficulty removing and then reinserting the BCM. My remedy is therefore going to be a cut and splice operation involving the passenger and driver heated seat looms where they run side by side in the passenger cill. On the face of it all that is involved is cutting and swopping power cables A2 & A5 and doing the same to the control cables C40 and C43.
EDIT:
@Lozzy15 I am even more confused having just checked the Kufatec intructions because they coincide exactly with your guide, ie BCM pins 5 and 40 for drivers side, pins 2 and 43 for passenger side and pin 56 common to both sides. I am also pretty sure I wired correctly to each pin because of my hand marked dash against each one done after double checking the pins/wires after installation in the BCM connectors.