The blind spot monitor is a system that has 2 functions;
Assists the driver in making the decision when changing lanes
Assists the driver when backing up
These functions use same sensors.

Pressing the switch turns the system on or off. When the switch is set to on, the switch’s indicator illuminates and the buzzer sounds. Common switch for blind spot monitor function and rear cross traffic alert function.
Blind spot monitor function: when a vehicle is detected in the blind spot, the outside rear view mirror indicator comes on while the turn signal lever is not operated and the outside rear view mirror indicator flashes while the turn signal lever is operated.
Rear cross traffic alert function: when a vehicle approaching from the right or left rear of the vehicle is detected, the outside rear view mirror indicators flash.
When a vehicle approaching from the right or left rear of the vehicle is detected, a buzzer sounds from behind the left-hand rear seat.
The outside rear view mirror indicators visibility
When under strong sunlight, the outside rear view mirror indicator may be difficult to see.
Rear cross traffic alert buzzer hearing
Rear cross traffic alert function may be difficult to hear over loud noises such as high audio volume.
When there is a malfunction in the blind spot monitor system
If a system malfunction is detected due to any of the following reasons, the bsm warning light will come on
Certification for the blind spot monitor system
Fcc id: oaysrr2a
This device complies with part 15 of the fcc rules. Operation is subject to the following two conditions:
Fcc warning
Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.
For vehicles sold in canada
Applicable law: canada 310
This device complies with industry canada licence-exempt rss standard(s).
Operation is subject to the following two conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device.
Frequency bands: 24.05-24.25 Ghz
Output power: less than 20 milliwatts
Caution
Handling the radar sensor
One blind spot monitor sensor is installed inside the left and right side of the vehicle rear bumper respectively. Observe the following to ensure the blind spot monitor system can function correctly.

The blind spot monitor
functionInstallation
Notice:
Do not heat the vehicle body, emblem and name plate
excessively.
Hint:
When installing the emblem and name plate, heat the vehicle
body, emblem and name plate using a heat light.
Standard heating temperature
Install no. 4 Back door name plate (for 4wd)
Clean the vehicle body ...
Seat heater system
Parts location
System diagram
Problem symptoms table
Hint:
Use the table below to help determine the cause of the
problem symptom. The potential causes of the symptoms are
listed in order of probability in the "suspected area" column
of the table. Check each symptom by check ...
If your vehicle needs to be
towed
If towing is necessary, we
recommend having your
vehicle towed by your
Toyota dealer or commercial
towing service, using a
wheel-lift type truck or flatbed
truck.
Use a safety chain system
for all towing, and abide by
all state/provincial and local
laws.
Situations when it is necessary
to contact d ...