What is the reason for the constant flashing of the Toyota differential lock light?

[StThomas]

Toyota differential lock keeps flashing due to a fault in the engine coolant level sensor, which is located on the coolant expansion tank cap. When the engine coolant level drops, the warning indicator light is activated, as this switch is normally closed. Here are some details about the differential lock: 1. Function: The central differential lock is a locking mechanism installed on the central differential, used in four-wheel-drive vehicles. Its purpose is to enhance the vehicle's ability to traverse rough terrain. When one of the drive axles spins freely, the differential can be quickly locked, turning the two drive axles into a rigid connection. This allows most or even all of the torque to be transmitted to the non-slipping drive axle, maximizing its traction to generate sufficient driving force and enabling the vehicle to continue moving. 2. Types: Different differentials employ various locking methods. Currently, the common differential locks include the following five types: forced locking, high-friction self-locking, jaw-type, Torsen-type, and viscous coupling.