chimaera

VCDS has a function called Long Coding Helper which shows you what the options are for each byte in the long coding. You can use that to tick the boxes that apply to your car and it will generate the long coding.

You're saying the coding in the ABS module has been set to all zeroes? You should be able to use the long coding helper to walk you through setting it up again.

You should have a look at this thread, it sounds like a similar issue:

Ok. Does it work when the engine is running? If not you could check fuse 13 - it supplies power to the diagnostic socket. It's also possible that your diagnostic tool is not compatible with the car. Has it worked on other VAG models of a similar age?

When one of mine died I did a trawl of the local motor factors until I found one that could source it.

Ignition has to be on before diagnostics will work.

Do what @langers2k said above. There's no shortcut or quick fix option here.

LCD screens usually have a polarising filter on them. If you look at them from the wrong angle with polaroid sunglasses the light from the screen is completely blocked.

It's worth phoning your dealer for a price. I replaced mine a few months ago and it was only about €35 from the local dealer here.

The DSG oil cooler has its own thermostat separate to the engine's one.

Grooved/drilled disks will reduce glazing a little since there's an edge on the grooves/holes that can scrape off the glazed layer. From a cooling point of view, it comes down to a balance between increased cooling from the larger surface area and reduced heat dissipation from the pads due to the smaller volume of metal available to absorb heat. You're depending on the designer of the disks to have done their job there.

What year is your car? Does it have start/stop? If so, was the battery coded to the vehicle after replacement? To be honest, going flat after sitting for a week doesn't sound too far off in a Superb. There's a lot going on electrically, even when the vehicle is off.

While the numbers of collisions and fatalities may have been stable, the number of cars and drivers on the road is steadily increasing year to year. More people spending more time on the road should increase the number of collisions and deaths; that those numbers are stable suggests that actually yes, the safety tech is doing its job to make the roads safer. It's a massive problem with media reporting on road safety: all of the focus is on the absolute number of deaths/injuries rather than the rate per million vehicle kilometres or some other similar metric. While each of those deaths is a tragedy at the individual human level, it's disingenuous to focus on those numbers alone when discussing the effects of road safety technology improvements.

Facelift model uses D3S. Pre-facelift is D1S.

That's only for the Superb mk3; OP here has a mk2.

You should find someone with VAG diagnostics and get the battery coded to the vehicle. If it's an AGM battery in a vehicle with a battery management module, it must be coded to work properly. It may not be the cause of this issue but it is still problematic and won't help you get to the bottom of it.

Engine tech has been driven by the need to meet ever stricter emissions rules, and we're well into the diminishing returns space with internal combustion technology. When it comes to safety technology, the lowest common denominator always applies. You design for the least capable driver you can conceive of. Even those of us who consider ourselves capable can be assisted by safety technology. Last summer I came within a few metres of a head-on collision thanks to a muppet who decided to overtake several cars on a bend. The brake assist feature on the Superb definitely contributed to making it a near miss rather than a collision. The technology is well enough designed to stay out of the way unless it's needed. I would say this is true of most driver assistive technologies as they have advanced. Once a piece of technology is available it's only a matter of time before it trickles down from the luxury/sporty end of the market to the average family car, often hastened by regulatory pressure. ABS is a good example of this: it started becoming common on cars during the mid to late 90s, and was eventually mandated by the EU on new cars built from July 2007. DRLs have followed a similar path. Driver comfort features are the sort of thing that trickle into use and reach a point where customers ask for them next time once they have used them. There are several features on my Superb that I never missed on my previous car when I didn't have them, but which I'd be extremely reluctant to go without now. Another thing that tends to happen is that technology platforms introduced for one purpose inevitably get expanded as engineers think up new ways to use the technology that's available. A lot of vehicle systems switched from direct wiring and switches/relays to using ECUs to control them because it reduced the amount of wiring needed in the vehicle, and CANBUS allowed a lot of data to be shared between different modules using just two wires. But once you have an ECU controlling stuff, the engineer will look at it and think "what else can I do with this?". Tyre pressure monitoring via ABS is a good example: there are already speed sensors on each wheel collecting data and sending that back to the ABS controller, all it takes to add tyre pressure monitoring is add a few lines of code to the software in the ABS and instrument controllers, and add some warning lights and now you have tyre pressure monitoring with very little extra effort. A lot of clever little features will have evolved this way. It's also worth remembering that all of these addition technologies have arrived slowly over time. 1989 was 32 years ago - that's a very long time in technology development, and makes for a very stark comparison with 2021, but if you compared 1989 with say 1990 or 1991, the changes would be marginal.

The point of failure in the wiring harnesses tends to be inside the bellows between the door and the body, not at the connector. On the Superb 2, the factory fix was to lengthen the wires at this point to reduce the strain on them. I can't see how stuffing the connector with grease is going to reduce the strain on these wires.

Short to ground suggests failed sensor or wiring damage in the right headlamp swivel position sensor. Replacing the control module probably won't help at this point.

The service manual says an AGM battery can be charged while connected to the vehicle but the negative connection of the charger should be connected to an earth point on the body rather than directly to the battery's negative terminal.

You can buy them from https://erwin.skoda-auto.cz/erwin/showHome.do A 24 h subscription is about €30 and is lots of time to grab all of the service manuals for your car. You can get the build sheet there too which lists all the PR codes for your car.

Each headlamp has a 10-pin connector going into it carrying all electrical signals into it. The white wire on pin 8 on each connector activates the focus shutter for main beam. I would suggest tapping those to switch a relay to turn on your auxiliary lamps. This should avoid problems with the bulb-out warning system. Get a power supply for them from the permanent 12 V bus bar on the fuse panel.

OP is in Finland, regulations may be different there. They are also planning to have them switch on with the main beam rather than the dipped beam.

An OBD tool won't be able to access the airbag controller as it is not part of the OBD standard.

If you turn on the ignition while any part of the airbag system is disconnected you'll get a warning light that can only be reset with diagnostics. If you left the ignition off it would explain why you got no warning. Disconnecting the battery will make no difference for the OP at this point.