Failing to investigate the cause of the following warnings may lead to the system operating abnormally and possibly cause an accident.
Have the vehicle inspected by your Toyota dealer immediately.


Stop the vehicle immediately.
Follow the correction procedures.Horn Circuit
DESCRIPTION
When the theft deterrent system is switched from the armed state to the alarm
sounding state, the main body ECU (driver side junction block assembly) transmits
a signal to cause the horn to sound at intervals of 0.4 seconds.
WIRING DIAGRAM
...
Installation
INSTALLATION
PROCEDURE
1. INSTALL SEPARATE TYPE FRONT SEATBACK COVER
(a) Using a tacker, install the separate type front seatback heater to
the end of the separate type front seatback cover with 12 new tack pins.
NOTICE:
Be careful not ...
Random Access Memory (RAM) (P0604)
MONITOR DESCRIPTION
The ECM continuously monitors its internal memory status. This self-check ensures
that the ECM is functioning properly. It is diagnosed by internal "mirroring" of
the main CPU and sub CPU to detect Random Access Memory (RAM) ...