2007 FX35 mode selector not working

[Nathan66]

I have a 2007 Infiniti FX35 with the mode selector not working. It starts at the feet and cycles through each of the three selections. It will spend about a minute at the feet, then a minute at the feet and forward vents, then go to the forward vents for about a minute, then repeat. Everything else on the dash, control and car are working just fine. Help?

[VStar650CL]

That sounds like maybe the HVAC (Unified Meter and A/C Amp) is stuck in "self test" mode. I'd try disconnecting the battery first to force it to boot cold, if it's a data corruption issue that may fix it. It's also possible the mode servo has lost its mind. It doesn't look like a huge job to get at it, the glove box and blower housing need to come out but it's not like the whole dash is involved. See ATC-130 here:
https://www.nicoclub.com/service-manual ... %2Fatc.pdf

[Nathan66]

Darn. I wish the battery disconnect worked. You're saying next step is to replace the mode selector motor?

[VStar650CL]

The servos are all on a common LAN with the HVAC, so if the other servos all work properly (both mixes and the recirc) then it's very unlikely the problem is in the HVAC or the LAN bus wiring. It can't be an obstructed door because it's cycling through the positions. That pretty much leaves a psycho servo as the only plausible culprit.

[Nathan66]

VStar, you are absolutely correct. It started working properly today. LOL But I learned a lot about all of that in the process of my research in the last 26 hours.

[VStar650CL]