I'm probably just doing something wrong here but I can't seem to figure out what. Everything works perfectly fine if I'm hand flying. LNAV and VNAV are operating correctly etc. What happens is as soon as I engage CMD A I get the yellow CWS P indication, MCP changes to Speed hold, and I can't engage LNAV or LVL CHG. It doesn't matter if I'm in the climb or cruise. Any suggestions?