P80 C70 Hvac Drivers side only hot air, damper motor position, map of position counter, internal pictures

CoupeC70 · Post by **CoupeC70** » 09 Jun 2026, 04:57

Hi there,

Only hot air is coming out on the driver's side, no matter what temperature I set.
Everything works fine on the passenger side.

Is the ECC unit possibly defective? Does that even happen with the C/V70?

Post by **Sveedy** » 09 Jun 2026, 08:12

I have the same exact issue. In my case a piece of plastic fell out of the passenger side foot-well vent. I believe that is was part of one of the blend doors in the HVAC system. So for now I have the dash vents on the drivers side closed, and the ECC set to dash vents on the passenger side only. Within a few minutes things are tolerable.

The fix involves removing the dash in order to get into the vent system. A good time to reinforce the dash mounts.

CoupeC70 · Post by **CoupeC70** » 09 Jun 2026, 08:18

Aha, okay—and a faulty ECC unit is also a possibility?

My dashboard was already out for repair, he he

Post by **scot850** » 09 Jun 2026, 08:30

It is possible but more likely the flaps internally are faulty or one of the servo motors is bad.

Neil.

Post by **misha** » 10 Jun 2026, 23:33

C70 have fully obdII ecc system.
Read the codes with Vida to see what is going on.

CoupeC70 · Post by **CoupeC70** » 11 Jun 2026, 01:48

Dont have VIDA, will try with 850 Android App

It isn't always warm, after all. It still seems to be working—sometimes better, sometimes worse.

Could the interior temperature sensor be responsible for this? It’s just strange that the problem only exists on the driver's side.

Post by **misha** » 11 Jun 2026, 15:33

No...850 app will not work even on 850 for ecc readout since 850 ecc still produce flash codes.

You need VIDA only for models after '98.

CoupeC70 · Post by **CoupeC70** » 11 Jun 2026, 16:17

But the website says it can read ECC.
And I read that somewhere here on the forum, too.

Or did I misunderstand?

Post by **misha** » 12 Jun 2026, 00:31

It will not work on 850...if it have s,v,c,xc70 code readout...then yes...since their ECC is fully obdII compliant.

CoupeC70 · Post by **CoupeC70** » 12 Jun 2026, 01:41

I have C70 2000

It's cold outside today.
I turned up the temperature on both sides, and warm air is coming out.
However, when I lower the temperature again, cold air only comes out on the passenger side. Nothing happens on the driver's side. Yesterday, though, cold air was coming out on the driver's side, and I even had the A/C turned on.