If communication between the electronic key and vehicle is interrupted or the electronic key cannot be used because the battery is depleted, the smart key system and wireless remote control cannot be used. In such cases, the doors can be opened and the engine can be started by following the procedure below.
Locking and unlocking the doors

Use the mechanical key (→P. 33) in order to perform the following operations:
1. Locks all doors
2. Unlocks all doors Turning the key rearward unlocks the driver’s door.
Turning the key once again unlocks the other doors.
Starting the engine
Ensure that the shift lever is in
P and depress the brake pedal.

Touch the Toyota emblem side of the electronic key to the “ENGINE START STOP” switch.
If any of the doors is opened or closed while the key is being touched to the switch, an alarm will sound to indicate that the start function cannot detect the key.
Press the “ENGINE START STOP”
switch within 10 seconds of the buzzer sounding, keeping the brake pedal
depressed.
In the event that the “ENGINE START STOP” switch cannot be operated, contact your Toyota dealer.
Stopping the engine
Shift the shift lever to P and press the “ENGINE START STOP” switch as you normally do when stopping the engine.
Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the electronic key battery be replaced immediately when the battery is depleted.
Changing “ENGINE START STOP” switch modes
Within 10 seconds of the buzzer sounding, release the brake pedal and press the “ENGINE START STOP” switch.
The engine does not start and modes will be changed each time the switch is pressed.
If you cannot operate back door opener
If the vehicle battery is dischargedInstallation
INSTALLATION
CAUTION / NOTICE / HINT
HINT:
When installing the symbol emblem, No. 1 back door emblem and No. 1 roof side
mark, heat the vehicle body, symbol emblem, No. 1 back door emblem and No. 1 roof
side mark using a heat light.
Standard:
...
Open in Occupant Classification ECU Battery Positive Line (B1794)
DESCRIPTION
DTC B1794 is stored when a malfunction is detected in the occupant classification
ECU.
DTC Code
DTC Detection Condition
Trouble Area
B1794
One of the following conditions is met:
...