So I've recently discovered my MY21 T6.1 Caravelle has the basic auxiliary coolant heater as this winter was cold enough for it to kick in - I had assumed I didn't due to penny pinching in the 6.1 line elsewhere...
I don't really need a heater I can have on for ages camping, because we don't do that, and while I like the remote warm up on the EV again we don't really use the van like that.
What I do use a lot though is the "REST" function where the heating can run for ~20 minutes from the residual heat when we are parked up and picnicking.
What I'd really like is the ability to just force the heater to run during those periods. I'm aware that this will load the starter battery and I'm OK managing that - if we use it a lot I'm aware we can intercept the power for the heater and main blower and move those to a leisure battery (which I don't currently have). Essentially I'd be happy with just an on off switch mounted on the passenger seat base that forced the heater on when I wanted it, nothing more fancy.
This is the details I can read with OBD11 - I believe the version ending in 1 means it's not got the right VW firmware for parking operation
So what are my options here?
This is going to be infrequent use so is there any capability in OBD11 to just kick the heater on occasionally by triggering any test function?
I've spoken very briefly to Danhag about their plug in solution, though I'm not sure that currently they will ship directly to the UK. It's expensive but as I'm running a VW Warranty if it will do the job the ability to just remove it and return to stock is attractive. I assume this is commanding the heater using testing functions.
Is there a simple way of upgrading the firmware on a 6.1 - this seems to be still a bit on the cutting edge of knowledge?
If I replaced the ECU I assume that will require quite a lot of physical tinkering to achieve it - and at the end will it still operate as an auxiliary heater during winter driving or would I need to turn it on manually?
Would I be better off just finding someone to fit a secondary Eberspacher/Webasto air heater and be done with it? (I'm aware there are cheaper units but I know the 2 big brands from the marine world and would prefer to stick with those)