Rear Differential Lock Button.
Vehicle: Found in some Toyota Hilux models.
- It increases off road capability and control in difficult off road driving conditions.
- Should be used in conjunction with L4.
This is the official sticker for the switch:
As a note,
- Line one is reactive operation; most of the time when a vehicle gets stuck the resistance offered will overcome available traction and operating the diff lock won’t help.
- Proactive operation ( operating before going into the situation ); will help drive through the situation as the vehicle still has momentum.