Hint:
Performing a system check enables the system, which consists of multiple actuators, to be operated without removing any parts. In addition, it can show whether or not any dtcs are set, and can detect potential malfunctions in the system. The system check can be performed with the intelligent tester.

Active test
Diagnostic trouble code chartIf a warning light turns
on or a warning buzzer
sounds
Calmly perform the following actions if any of the warning lights
comes on or flashes. If a light comes on or flashes, but then
goes off, this does not necessarily indicate a malfunction in the
system. However, if this continues to occur, have the vehicle
inspected by your toyota dealer.
Stop t ...
Downhill assist control operation switch (test mode dtc)
Description
The downhill assist control switch is connected to the skid control ecu in
the abs and traction
actuator.
Dtc c1379/74 can be detected when the downhill assist control switch sends the
downhill assist control
switch signal or test mode ends. Dtc c1379/74 is output only in t ...
How to proceed with troubleshooting
Hint:
Use these procedures to troubleshoot the supplemental
restraint system.
*: Use the intelligent tester.
Vehicle brought to workshop
Inspect battery voltage*
Standard voltage:
11 to 14 v
If the voltage is below 11 v, recharge or replace the battery
before proceeding.
...