Adjust the engine idle speed periodically on the engine at normal operating temperature.
To adjust the idle speed:

Engine oil and filter change
Throtile cable playSpecifications
Service data
Fi sensors
Tightening torque specifications
Note
the specified tightening torque is described in the following.
“Exhaust control system construction” “exhaust system components”
Reference: for the tightening torque of fastener not specified in this ...
DTC table
In the lcd (display) panel, the malfunction code is indicated from small code
to large code.
*1 To get the proper signal from the throttle position sensor, the sensor basic
position is indicated in the lcd
(display) panel. The malfunction code is indicated in three digits. In front o ...
DTC “c28” (p1655): secondary throttle
valve actuator (stva) malfunction
Detected condition and possible cause
Detected condition
Possible cause
The operation voltage does not reach the stva.
Ecm does not receive communication signal from the
stva. Stva can not operate properly or its motor locked
Stva malfunction.
...