Hi, the unit control price is around £600 brand new, you can buy it from VW/Audi and also you can choose to buy an used one, around £90 - £120 on ebay, and also the unit control will required to be programmed for your car.
In my case the code for unit control was this one 4M0907355B, but can be...
Not yet, one service told me is the adblue pump faulty and have to be replaced. But i will try another service to see if is the same thing they saying.
As far as i read online, you are right, p21ca is low voltage control module, nothing to have with the pump.
Will look soon for a second opinion.
Yes, didn't drive the car anymore, on the way to a service got the same fault on
Yes, i didn't drive the car anymore, and today on the way to a service, i got the same fault in my dash.
Let's see what the service saying.
Just got engine light on today, after yesterday i top up ad blue. To be honest i top up with ad blue from the petrol station, but is not the first time i am doing that.
I read the faults, and got me just one P21CA.
I mention i do not have warranty anymore, just ended in november last year.