Hi Folks,

Well after 13 months, my G seems to have developed a problem with its automatic climate control. I have it set on Auto at 20C (Canada), once the engine heats up, the fan goes up to full speed, and hot hair comes a blowing in. Problem is that the fan always stays on max, and the hot air keeps coming in, heating the interior up way past 20C. Never did this before, just noticed it now.

Anyone else ever have this problem, if so whats the fix?

 

I think the system regularly overshoots its setpoint during warmup. I'm in the temperature control business and my best guess is that they average the temperature the sensor is reading over time to prevent short cycling of the system and that as a result, the fan runs longer and the heat stays full bore. Either that or the sensor stays cold due to its proximity to the cold dash which takes time to heat up. Just an educated guess.

'03 G35/6MT Sedan Black/Black

 

After my service several months ago, when they fixed the break light switch (whatever that recal was.) A similar thing happened to me, on mine I could set the temperature to the lowest setting (60F) and it would blow cold air. If I set the temperature 1 degree higher (61F) it would blow max hot air. Since it was in the summer this wasn't too bad, as I just set the climate to max cool until I could get back in (was waiting on another broken part as well.) If it had been during the winter it wouldn't have been very good.

2003.5 G35 Sedan