PMDG 737 Autopilot won't work

[thijm20]

Hello everyone,

For a few days now I'm struggling with an issue with the autopilot of my PMDG 737.

The speed autopilot works fine, but the heading and altitude won't. I followed checklists closely. And I read a lot of forums. But still: it won't work.

 

I hope anyone has the solution for me

[Pegaso]

Hmmm, if everything worked correct before and you are sufficiently professional with programming the CDU maybe there is a corrupt file. Uninstall and reinstall the plane if you didn't already. Probably you mean the the  Speed knob and Autothrottle by speed autopilot. Does the Autopilot knob activate/lighten when pressed?  And even a real pilot must confess that while entering flight data at any step pressing the required <Enter> may be forgotten, and then LNAV and VNAV cannot work. Is your route displayed as a solid line without gaps?

[kevinh]

Reinstalling is unlikely to fix it. Check the CDU for failures. There is an autopilot linkage which can fail and this will persist unless you reset it. 

[Ephedrin]

Could you please explain what exactly is happening (and has happened on your computer)

if tjere have things changed on your system a repair using the installer might work. Though I doubt it as nothing has actually changed on the 737 and there are no complaints about windumb updates atm.

so the autothrottle works? Only IAS mode?

what happens if you press the command button(s)? Are there lights on on the MCP? Are there any FMA modes shown on the PFD? Or does is simply not react on clicks? 

 

My first guess would be that you don‘t load the plane up correctly. When your sim starts there have to be a default airplane turning in the aircraft select window. 

Second guess: corrupted panel state. Load the airplane in „default panel state“ via the CDU - PMDG OPTIONS.

third guess: as mentioned above, system failure. 

 

Tbh it doesn‘t make sense that a corrupted installation would only affect the AP. I would have read this the very first time.