After winter storage I notice Excessive Brake Pedal Travel and after a short drive the BAS/ESP light comes on. Restart engine and light goes out but returns after another short drive. Braking seems to be OK. I have re calibrated steering wheel and battery voltage is good, Where should I start to trouble shoot and correct this problem?

 

I had this same problem several years ago, went to take it out of storage and the pedal almost went to the floor. I bled the brakes and they were fine. Funny thing about this is I store it every winter and it only happened once.
I would start with bleeding thr brakes.

 

start with a brake fluid flush, inspect for leaks.

 

This just happened to me last week when I took my car out of storage for the first winter I have owned the car. I did a brake fluid flush and all is good now.

 

My car has had this happen several times after hibernation. I bled the front brakes, no difference. I found that bleeding the rear brakes resolves my issue.