Cadillac: 1993 cadilac a/c prob & loss of engine power, power steering rack, vacuum leak

Question
I have a 1993 cadilac sedan deville 4.9L.  My problem is this.  Today as I was driving I there was a sudden surge in power and then my ac was inop.  It pulled a ses code E40 which doesnt seem to make sense to me.  According to the book E40 has to do with power steering.  Also at the same time it seems that I lost some of the power assist to my brakes when at low RPM.  I cant figure out how all of these are related or even where to start.  I reset the E40 code and have and the ac still is not blowing cold air.  The fan motor is working fine and the control stays in the auto position but not cold.  Please advise and of course thank you in advance.

Answer
On the power steering RACK under the car or on one of the power steering lines is a pressure sensor that has most likely failed causing your code.

Anytime a cODE sets the AC is disabled until the code is fixed.

As to your brakes sounds like a massive vacuum leak that you will have to locate.