Manual Yaris transmission fluid check and change

[komichal]

Here is a nice tutorial: https://www.yarisworld.com/forums/showthread.php?t=8912
No need for a fancy filling tool for this job. A funnel with a piece of hose will do just fine (filling from top).
If you decide to change the oil then use only original Toyota. Multiple people (including me) had multiple issues with quality non-original oils (Mobil 1, Valvoline,...) despite their full conformity with the specs.