Hint:
Using the intelligent tester's data list allows switch, sensor, actuator and other item values to be read without removing any parts. Reading the data list early in troubleshooting is one way to save time.

Fail-safe chart
Diagnostic trouble code chartHitch
Trailer hitch assemblies have different weight capacities. Toyota recommends
the use of toyota hitch/bracket for your vehicle. For details,
contact your toyota dealer.
If you wish to install a trailer hitch, contact your toyota dealer.
Use only a hitch that conforms to the gross trailer weig ...
Rear occupant classification sensor rh circuit malfunction
Description
The rear occupant classification sensor rh circuit consists of the occupant
classification ecu and the
rear occupant classification sensor rh.
Dtc b1783 is recorded when a malfunction is detected in the rear occupant
classification sensor rh
circuit.
Wiring diagram
...
Terminals of ecu
Check instrument panel junction block (main body ecu)
Measure the voltage of the connectors.
If the result is not as specified, the junction block
(main body ecu) may have a malfunction. ...