When switching the Low four wheel option, the center diff lock light also comes on indicating it is engaged. . What is the cause ?

What is your question?

The problem occurs every time it is switched from 4 high to 4 low. It is a manual landcruiser 200 gx diesel 2011 model

What makes this problem better or worse?

All the time

How long has your 2011 Toyota Land Cruiser had this problem?

Recently in the last couple of weeks