Heater Climatronic thermostat issues?

[reserves]

Does anyone know where the thermostat is for the A/C? Is it built into the ac unit itself?

Just picked up a low mileage 2017 T6 California.

Something seems off with the heating.

It has the Climatronic / 3 zone A/C heating.

Issue is it blows cold air unless you set the heating to 26c, then it blows really hot air, the difference between 25.5c and 25c is massive so doesn’t seem right.

I’ve had other T6’s where I’d leave the setting on Auto at 22c and it would be plenty hot enough.

I’ve scanned the car with VCDS and doesn’t pick up any errors around this.

Any ideas please?

 

[n10n]

Cabin temperature sensor is circled in red in below photo. Afaiu there’s no A/C thermostat really, just temperature sensors at vents, the one in image below and maybe (?) some more in the back.

You could try to take a blockmap of 08 - Auto HVAC as described in post Air conditioning not working. Please take one when it blows cold and another when it blows hot and post the blockmaps here. Maybe someone notices something off in them.

 

[reserves]

Cabin temperature sensor is circled in red in below photo. Afaiu there’s no A/C thermostat really, just temperature sensors at vents, the one in image below and maybe (?) some more in the back.

You could try to take a blockmap of 08 - Auto HVAC as described in post Air conditioning not working. Please take one when it blows cold and another when it blows hot and post the blockmaps here. Maybe someone notices something off in them.


View attachment 218969

Perfect. Thank you.

I’ll measure those blocks and post back

 

[reserves]

Managed to take some readings.

Inside temperature seems off to me. It was’t over 22c in the cab. It was freezing.

I wonder if swapping out the unit above would solve the problem. Expensive thug to try.

 

[Ads_Essex]

Managed to take some readings.

Inside temperature seems off to me. It was’t over 22c in the cab. It was freezing.

I wonder if swapping out the unit above would solve the problem. Expensive thug to try.

View attachment 219586

If you know someone with the same climatronic HVAC unit, plugging theirs in may assist with fault finding (that’s presuming the thermostat sensor is built in to the unit, which I’m sure I’ve read on here is the case). It’s a few bits of trim and some T20’s if memory serves me right.

Failing that, is this where those little white heater flaps come in to play - the ones that keep snapping? I thought mine had gone, but it turned out to be a loose connection at the back of my climatic HVAC unit (user error).. unless yours has been out, or you’ve had head unit work done, yours shouldn’t be loose.

 

[n10n]

Managed to take some readings.

Inside temperature seems off to me. It was’t over 22c in the cab. It was freezing.

I wonder if swapping out the unit above would solve the problem. Expensive thug to try.

View attachment 219586

I think the inside temperature reading is known to not really reflect reality.

Even if the inside temp sensor was broken it would be weird to cause a step change from hot to cold like that, unless if the inside temperature somehow would change wildly with temperature controls.

Something like @Ads_Essex linked sounds more plausible. Although I think that particular issue means only hot or cold would be ever output. Also I don’t recall anyone reporting that issue with Climatronic (doesn’t mean there hasn’t been one.)

 

[reserves]

Thanks both. I’ll check the white flaps!

I’m also going to blow a hair dryer at the inside temp sensor to check if it’s actually reading anything

 

[n10n]

Thanks both. I’ll check the white flaps!

I’m also going to blow a hair dryer at the inside temp sensor to check if it’s actually reading anything

Good idea!

 

[n10n]

Browsing through some SSP material for Climatronic (http://www.volkspage.net/technik/ssp/ssp/SSP_208_d2.pdf) I noticed this on page 12:


Now, 24° is awfully close to 23.9° inside temperature shown by the measured values - coincidence? If the control unit thinks the inside temperature really is 24°, it all kind of makes sense - you have to push temperature control clearly above that to get heating.

Then, on page 34 we have a note about self diagnostics that *may* be available. Although this talks about VAG testers they might be available through VCDS as well - if they exist. The SSP is by no means T6 specific and probably pretty old.



Edit: part1 of above SSP is http://www.volkspage.net/technik/ssp/ssp/SSP_208_d1.pdf

 

[reserves]

Browsing through some SSP material for Climatronic (http://www.volkspage.net/technik/ssp/ssp/SSP_208_d2.pdf) I noticed this on page 12:

View attachment 219646
Now, 24° is awfully close to 23.9° inside temperature shown by the measured values - coincidence? If the control unit thinks the inside temperature really is 24°, it all kind of makes sense - you have to push temperature control clearly above that to get heating.

Then, on page 34 we have a note about self diagnostics that *may* be available. Although this talks about VAG testers they might be available through VCDS as well - if they exist. The SSP is by no means T6 specific and probably pretty old.

View attachment 219654

Edit: part1 of above SSP is http://www.volkspage.net/technik/ssp/ssp/SSP_208_d1.pdf

Thanks for your detailed reply.

I managed to scan the car again (after a windows update killed my Bootcamp windows install)

The inside temp was 16.3 so that looks to be working or at least reading / changing values.

I measured a bunch of values on a drive and they all seem normal-ish.

Will post logs later.

To be clear my status and issues are:

- Heat does blow hot but only at temps around 26 or above
- Turning the heating down to 25.5 then I get cold air blowing and it’s a huge change in air temp being blown.
- I have Climatronic heating so have ruled out some of the dial problems with the manual dials (in terms of this physically being broke)

In terms of the white piece being broke under the drivers footwell is this something that can be causing the above?


Really appreciate all the help!