This question has bothered me since I've had my 06 CTT. When set on "Auto", the fan never goes above a low speed when heating. The cabin temperature eventually comes up and holds on the temp setting. Shouldn't the fan run faster as the coolant warms and until the cabin reaches the temperature setting? With the manual controls, all the functions and fan speeds operate as expected. Do I have a problem?

 

That's how mine works. As soon as the coolant warms up, the blower ramps up and then back down as the cabin reaches set point. Let cold air in by opening a window and it ramps back up. It also depends on outdoor temperature; if it's mild, the fan speed may only go up a few bars, near 0° and it'll max out on speed right after the coolant warms up.
Also, if I press one of the fan switches, it'll hold that speed. Press AUTO again and the blower will adjust on its own again.