Hi,
I have a 2011 ASX 2.0L (gas), owned from new, here in Philippines.
It has developed a confusing problem with the Aircon/Climate control and I wonder whether anyone has come across a similar issue.

The vehicle has a single zone climate control - there is no differentiation left/right, front/rear. The ventilation all passes through a single fan and single heat exchanger chamber.

To service the system fully, requires windshield and entire dashboard removal, which I have not done.

The problem is that, when set to 'cold' the air coming out of vents on the driver's side is reasonably cold. The air coming out of vents on the passenger side is tepid/warm.

When set to hot, hot air comes out of the vents on both sides.

As far as I can judge, the airflow from vents on both sides is the same speed/force, depending on the fan speed. The fan appears to be working normally.

Externally, I can see all the damper motors/levers moving. I have detached the air mixing damper motor, and that is operating normally, Moving the damper manually has exactly the same effect as when using the automatic control.

How can this be? I cannot understand how the air can come out at significantly different temperatures on the two sides!

The only, highly improbable, possibility I can imagine is that there is a hole in the air mixing damper flap (or the chamber itself), which favours uncooled air going to the passenger side.

My next step may be to disconnect the heater core from the engine cooling system, and see whether I can then get cold air from both sides.