Hello my 1999 Cl500 AC works and adjusts on both sides, however the driver side will not get hot and always seems to blow cold. The climate control is diagnostics is reading code EB1234 which is the sun sensor. I have the sensor on order however reading through the forums it appears that it may not be the problem. I checked the DUO Valve and they are working correctly. Hoping it is not the servo controlling blend door flapper. Any Ideas?