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 playSpecial tools and equipment
Recommended service material
Note
required service material is also described in the following.
“Front brake master cylinder components” “rear brake master
cylinder components” “rear brake pedal construction”
Special tool
...
Headlight bulb and position light bulb
replacement
Caution
when you touch the bulb with your bare
hands, clean the bulb with a cloth moistened
with alcohol or soap water to prevent
premature bulb failure.
Low beam bulb
Remove the combination meter. Refer to “combination meter removal and
installation” in section 9c .
...
DTC “c31” (p0705): gp switch circuit
malfunction
Detected condition and possible cause
Detected condition
Possible cause
No gear position switch voltage
Gp switch voltage is not within the following range.
Gp switch voltage > 0.6 V
Gp switch circuit open or short.
Gp switch malfunction.
...