If a problem occurs in the electric power steering system, the p/s warning light will come on in the combination meter and steering power assist will be stopped, fixed at a particular point, or decreased simultaneously to protect the system.

Hint:
The amount of power assist may be decreased to prevent the motor and ecus from overheating if the steering wheel is continuously turned when the vehicle is either stopped or driven at a low speed, or if the steering wheel is kept at either full lock position for a long time. In such cases, the amount of power assist returns to normal if the steering wheel is not turned for approximately 10 minutes with the engine idling.
Freeze frame data
Data list / active testIf a warning light turns on or
a warning buzzer sounds
Calmly perform the following actions if any of the warning
lights comes on or flashes. If a light comes on or flashes, but
then goes off, this does not necessarily indicate a malfunction
in the system. However, if this continues to occur, have
the vehicle inspected by your Toyota dealer.
Actions to ...
Gcwr, twr and unbraked twr
Confirm that the gross trailer weight, gross combination weight, gross
vehicle weight, gross axle weight and tongue weight are all within the
limits.
Gcwr*
2Wd models: 5985 lb. (2715 Kg)
Awd models: 6100 lb. (2765 Kg)
Twr*
1500 Lb. (680 Kg)
Unbraked twr*
1000 Lb. (450 Kg)
*: ...
On-vehicle inspection
Check ignition coil assembly and perform spark test
Notice:
in this section, the terms "cold" and "hot" refer to
the temperature of the coils. "Cold" means
approximately -10 to 50°c (14 to 122°f). "Hot" means
approximately 50 to 100°c (122 to 212 ...