The following warning indicates a possible problem in the brake system.
Immediately stop the vehicle in a safe place and contact your Toyota dealer.

If a warning light turns on or a warning buzzer sounds...
Stop the vehicle immediately.Disassembly
DISASSEMBLY
PROCEDURE
1. REMOVE STEERING RACK BOOT CLIP (for LH Side)
(a) Using pliers, remove the steering rack boot clip.
2. REMOVE STEERING RACK BOOT CLIP (for RH Side)
HINT:
Perform the same procedure as for the LH side.
3. REMOVE NO. 2 STEERING RAC ...
Removal
REMOVAL
PROCEDURE
1. ALIGN FRONT WHEELS FACING STRAIGHT AHEAD
2. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-)
battery terminal to disable the SRS system.
NOTICE:
...
Lost Communication with Rear Gate Module (U0230)
DESCRIPTION
DTC No.
DTC Detection Condition
Trouble Area
U0230
No communication from the power back door ECU (back door motor unit)
or back door closer ECU continues.
Power ...