Here's a 4 minute video showing how to read fault codes using VCDS.

I'm using a Seat Altea and I've disconnected the rain and light sensor to simulate a fault. The video shows how to read the fault code and view live data to confirm the lack of communication from the rain and light sensor.

I'm using VCDS with a HEX-V2 3-VIN enthusiast interface, and I am not going to use a VIN slot on the interface so you can see how you would read or clear fault codes and view live data on a friends car, or on a car you were thinking of buying without losing a VIN on your 3-VIN VCDS interface



Video transcript
Hello, this is Derek from ilexa
This is a quick guide to reading fault codes from a single module using a VIN-limited interface, in this case it's a three VIN HEX-V2 interface and I haven't registered it to any cars yet, so it has no VINs stored at all.

I'm going to choose Select and then I'm going to choose Central Electrics because I have disconnected the rain and light sensor
so I know there will be a fault.

VCDS prompts me, do I want to add this VIN to the interface?  It says it's currently not registered, would I like to add it?

In this case, I'm going to choose no and that will still allow me to read fault codes, clear those fault codes and look at live data, but I won't be able to do adaptations or codings or things like that on the module unless I allow VCDS to add that VIN to its list.

I'm going to read fault codes, and we have interior monitoring sensors intermittent and rain and light sensor, no communication.

The rain and light sensor, no communication is expected because I have disconnected it.

 I'm going to clear those, first off, I'll just click Save.

I'm going to save that and now I'm going to clear those codes.

And I'm expecting that the rain and light sensor fault code will come back but it might need the ignition cycling just to register it.

No, it's instantly come back however, the interior monitoring one is gone.
That was intermittent, so that's okay.

Now I'm going to look in the measured values and we're looking for the rain and light sensor. So, I'll type Rain into the search box to narrow them down, tick those two.

We have no communication and also we have no component info. So, that confirms again that the rain and light sensor is not talking to the rest of the car.

I will save that to the log and then I'll go done back out of there, and I'll close the controller and now I'm going to turn the ignition off, reconnect the rain and light sensor. Put the ignition back on and go back into Central Electrics.

Straight away we can see a difference there that there are four slave units now where there were only three previously and  the rain and light sensor part number has popped up in the slave list,

We'll go into Fault Codes and I'm expecting that to be intermittent now which it is.

I won't clear it just yet but I will save those to the log.

I kept the log open even though I closed the controller so that all of these saved files will be in a single file as a good record for this job.

And I'll choose Advanced Measure Values, type Rain again and tick those two.

And so, now this time I have the live value from the rain sensor.

There is indeed no rain and I have component info showing so that's a good sign, the communication is back and that's all looking good.

 I'm going to clear that code and we know what that fault was, so I don't expect that to come back and I'll just quickly read it again and that's it, and so, that's all done.

And I close the controller.