GX Rear Vent Flap Error

Sounds like a pain! Could be a loose wire, like trying to find a needle in a haystack. Does the climate control unit seem to be acting up in other ways, or just the rear vent? Have you checked the fuses?

Just the rear. Fuses look good. By 'acting up,' you mean what exactly? All other functions seem normal otherwise. Could it be the actuator?

If it's just the rear, actuator sounds plausible. But electrical gremlins are sneaky. Like a bad penny, they always turn up! Given the cost of parts and the fact that your AC no longer cools as it should I'd suggest getting it checked by a workshop.

Faulty connection confirmed. Sorted for 95€. Thanks for the advice.