2013 Allroad heater not working

[steel_3d]

Where is the location of the heater coolant valve on this car? 2013 B8.5. I took off the cowl, and the heater core hoses run straight from the engine, through the cowl, and through the firewall. I don't see a valve anywhere. Where do I find it?

I'm pretty sure the problem is the valve, because one heater core hose is hot, and the other just warm. I get no heat at any RPM.

[Smac770]

https://audi.7zap.com/en/usa/audi+a4...ol-4-2-155-210

Seems to imply that for US market flex fuel (7GB+TL6), the hoses run direct, no N422 coolant shutoff valve. Items 30/31/32.

The N422 is controlled by the J255 (08-auto hvac). Is there an output test under 08 that you can invoke for the climatronic coolant shut-off valve? Start that and see where the sound is coming from. You could also pull the climate control panel and look at the 20-pin; is there a white/red wire on pin 18?

The wiring diagrams document doesn't note the N422 as "maybe" for the B8.5 2.0T, so seems odd for it to be such.