Difficulty engaging autopilot

[Guest connor]

HelloI perform TO roll with LNAV and VNAV pressed in order to follow the FD bars on the initial SID. When I press CMD button, the AP does not engage but instead gives me an audible chime and the AP disconnect button (bar) pops open. In this initial climb, I repeat over and over, but the same thing happens repeatedly.It does eventually engage, but I am 5000-7000ft alt by then.What am I doing wrong????????Thanks for any help.Andy

[Guest UlfB]

Please post a picture of the main panel after take off and when you press the CMD button. It would help a lot.And please sign your posts at PMDG support forum with your full name.Ulf Bjarke

[downscc 1,325]

Please sign your full name in this forum. It should engage above 400AGL (above ground level), if not then there are a number of things that could be the problem such as not on an intercept course to first fix, discontinuites in the path, preflight incomplete, etc. It's really hard to tell with the limited info you gave us.