I have 1992 400e with 97,000 miles. It has vibration problem at stops while, it is idling. My check engine light comes on about once a day usually, right after I turned off the car and turn it back on. It then disappears after 10 secs and don't see it until the next day. I checked for codes and got 17 flashes. So, I am to assume a code 17
What is a code 17?