Visually inspect the isc valve if necessary.

Throttle body inspection and cleaning
Throttle valve synchronizationDTC “c40” (p0505 / p0506 / p0507): isc
valve circuit malfunction
Detected condition and possible cause
Detected condition
Possible cause
C40/P0505
The circuit voltage of motor drive is
unusual.
Isc valve circuit open or shorted to ground.
Air passage clogged.
Isc valve is fixed.
Isc valve prese ...
Regulator / rectifier construction
Regulator/rectifier
Regulator/rectifier bracket
Air intake pipe (rh)
Spacer
Wiring harness
Connect
the regulator/rectifier couplers under the wiring harness
10
N·m (1.0 Kgf-m, 7.0 Lbf-ft)
...
Modification
Modification of the motorcycle, or
removal of original equipment
may render the vehicle unsafe or
illegal. Obey all applicable equipment
regulations in your area.
The frame of this motorcycle is
made of an aluminum alloy.
Therefore, never make any modifications
such as drilling or weldin ...