Suzuki GSX-R750 Service Manual page 188

1A-116 Engine General Information and Diagnosis:
P1657-L (Use of SDS)
Step
1 1) Turn the ignition switch OFF.
2) Lift and support the fuel tank. Refer to "Fuel Tank
Removal and Installation in Section 1G (Page 1G-9)".
3) Check the EXCVA position sensor coupler (1) for loose
or poor contacts.
If OK, then check the EXCVA position sensor lead wire
continuity.
4) Disconnect the EXCVA position sensor coupler.
5) Check the continuity between Y wire and ground.
6) Also, check the continuity between Y wire and B/Br wire.
If the sound is not heard from the tester, the circuit
condition is OK.
Special tool
(A): 09900–25008 (Multi-circuit tester set)
Tester knob indication
Voltage ( )
(A)
Action
1
?
Yes
Go to Step 2 and go to
Step 4.
I837H1110153-01
I823H1110171-02
No
R or Y wire open, or Y
wire shorted to ground.