97Cavelier -
(Sorry about the accident but glad to see you are back)
I think that's an artifact of the Yaris' drive-by-wire throttle. In that case, the ECU/PCM may be defining it's own value for the throttle. If you think about it, 16 might mean maintain "idle RPM". Google google google, more on the subject ...
Drive by wire system is [uncool] - Toyota Yaris Forums - Ultimate Yaris Enthusiast Site
CarloSW2