There are no symptoms that I know of, I just wanted to learn how to read the codes.

KOEO: 11 11
Continuous: 15 15
KOER: 11 11

For code 15, one site says:
KAM (pin 1) was interrupted (was battery disconnected ?)

Another says:
EEC battery powered Keep Alive Memory (KAM) test failed.

I reset the codes, checked again and got 11's. Drove for a while, rechecked the codes and the 15 came back.

Any ideas?