Bought my 65 plate A207 350 CDI from Sandown Poole a year ago, impressed with the service, so after a recent (well before lockdown) disappointing experience after a service inquiry from MB Southampton (my nearest local MB Dealer) I decided I would use Sandown Poole for the service (service...
Having re-read your first post again, does this behavior happen on all 4 heater zones?, if it does then I agree with you're diagnosis of a faulty heater valve, but if it is isolated to a specific zone or left or right temp control then IMO it will be heater display control unit.
Depending on you're cars spec you will have to install an additional block of fuses in the boot fuse box, the main power for the seat heaters are fed from there, the loom also takes a feed from the front fuse box for the heated seat switches.
I retro fitted heated seats to my 202 230k. and I ended up taking the heated seat loom out of a scrap car, it also assisted in how the loom was connected and its cable route.
I did enquire at the main dealer for a loom and I seem to remember it was on back order but this was 10+ years ago...
I bought the Panamericana grill (same as the OP's), and fitted it to my 65 plate 207 cabriolet, liked it at first, but have gone off of it, and as my car is going to MB Salisbury next week for a service I thought I would put it back to standard.
I have now started to prefer the standard...
The seals between the actual oil cooler and the oil filter housing is a very common issue, they go hard, also the seal under the large nut in the housing, can be an issue but less so
Parts are cheap and took me less than an hour on my 55k to do all the seals...
Have you tried the key fob to unlock/lock the car in very close proximity to the door handle/lock? as the CLS utilities both RF and IR to unlock the vehicle (RF for distance, IR for close proximity).
Normally a failure of the distance unlocking/locking is an indication that the RF amplifier...
I believe the Aerial amplifier is behind one of the C pillar trims, N/S i think, though its failure is normally indicated by a failure of the remote locking from distance.
The screen elements in the CLS are quite prone to failing, I also believe there is a capacitor somewhere in the circuit...
For additional info adding of the under seat storage boxes is also possible on the A207 as I have done exactly the same thing to my "65" plate E350cdi, from the instructions given above, the process of fitting them seems to be identical.
Except I unbolted and disconnected the seats but just...
My understanding of the SAM in the early 208, is that everything will work but there MAYBE certain options that wont communicate to the diagnostic socket, but will work, these type of options were the rare ones so the chances are you will have no issues, just make sure the replacement SAM is...
I have used Renovo products and the genuine Audi products for both my Audi and Mercedes Convertibles and can recommend both.
The Audi products were a lot cheaper than I thought they would be.
I have also used the Autoglym products and wasn't that impressed.
Sorry cant help with the 203, now if it had been a 202........
Now the exact model is clarified I feel sure someone will pipe up.
Have you tried Utube? as there are loads of video tutorials on taking cars apart I always look there first, you might not be able to find something specific, you may...
Interested in this thread as I had a couple shear on my old AMG C class.
I google imaged the MB Pt. No. and like Moodi says looks very much like a riv nut.
If you scroll down the google image page there seems to be other similar solutions for Audi's, which simply look like a special pop...
The tube at the back of you're engine with the red cap IS NOT engine oil but a dipstick tube for the gearbox oil.
M113 engine in a 219 CLS has no dipstick tube the only way to check the engine oil level is in the cluster.
The engine has a saddle sump and two sump plugs.