Toyota FORTUNER 2021 Owner's Manual page 264

262
4-5. Using the driving support systems
When the sensor may not be correctly detecting the vehicle ahead
In the case of the following and depending on the conditions, operate the
brake pedal when deceleration of the system is insufficient or operate the
accelerator pedal when acceleration is required.
As the sensor may not be able to correctly detect these types of vehicles, the
approach warning (P. 257) may not be activated.
Vehicles that cut in suddenly
Vehicles traveling at low speeds
Vehicles that are not moving in the same lane
Vehicles with small rear ends (trailers with no load on board, etc.)
Motorcycles traveling in the same lane
When water or snow thrown up by the surrounding vehicles hinders the
detecting of the sensor
When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
Preceding vehicle has an extremely high
ground clearance