The recirc lite only tells you that the recirc switch is in the recirc position or is not in the recirc position. It does not check the position of the recirc door located under the glove compartment. What happened to mine is that the shaft from the recirc door gets disconnected from either the motor that drives the shaft or the door that it is supposed to close. Can't remember whether it is an electric motor or a vacuum device. The result is the same. When the switch is moved it makes a contact and either turns on the lite or turns it off. It is solely a swithch position indicator and a bulb checker. If the shaft is connected or not, the lite will reflect the switch position. Not the actual position of the recirc door. We went round and round with the dealer about this problem and they kept showing "no codes" but did not respect or trust our observations as to what was occurring. I finally got under the glove compartment and checked the acutal door movement. Not suprised to find the door was not moving with the switch.
pull the glove compartment out and look down in there. You will be able to see the rod and the door. Kind of a pain to work in there but it can be done. Mine fell off twice before i fixed it so it will not happen again.
Now that i am aware of the way the system works I can feel a small air pressure bump in the car with the windows up and moving the recirc switch back and forth. A very small increase in pressure occurs when you open the valve back for fresh air. that is my check for proper operation. Not the switch nor the lite, nor the OBD codes. None actually measure the position of the recirc door.
hope this helps.