GPSS Steering Issue

[TJRV8]

I have a dual screen Skyview system with AP Panel, pitch & roll Servos, integrated with a GTN 650, Expert Mode. AutoPilot tracks a flight plan from the 650 perfectly. But when I activate an approach, the system intercepts the final course, but then switches from GPSS to GPS and tracks consistently left of course. Far enough left to make it unusable. I have to switch to heading mode to intercept the course. This behavior just started. Up to now the system has worked perfectly. By the way, it tracks the glide slope normally. Any thoughts?

 

[Raymo]

What version software do you have installed? There was an improvement in this area for version 15.3.3.

Improved: Tracking of lateral guidance by the autopilot when on the final approach segment of a precision GPS approach.

 

[TJRV8]

I think I am running the latest software, but will check to make sure. Thanks