Suzuki GSX-R750 Service Manual page 162

1A-90 Engine General Information and Diagnosis:
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 GP switch coupler (1) for loose or poor
contacts.
If OK, then measure the GP switch voltage.
4) Support the motorcycle with a jack.
5) Fold the side-stand to up position.
6) Make sure the engine stop switch is in the "RUN"
position.
7) Insert the needle pointed probe to the lead wire coupler.
8) Turn the ignition switch ON.
9) Measure the voltage between the P and B/W wire, when
shifting the gearshift lever from 1st to Top.
Special tool
(A): 09900–25008 (Multi-circuit tester set)
(B): 09900–25009 (Needle pointed probe set)
Tester knob indication
Voltage ( )
GP switch voltage
0.6 V and more
((+) terminal: P – (–) terminal: B/W)
Is the voltage OK?
Action
1
V
(A)
(B)
Yes
• P wire open or
shorted to ground.
• If wire and
connection are OK,
intermittent trouble or
faulty ECM.
• Recheck each
terminal and wire
harness for open
circuit and poor
connection.
• Replace the ECM
with a known good
one, and inspect it
again. Refer to "ECM
Removal and
Installation in Section
1C (Page 1C-1)".
I837H1110068-01
I837H1110069-01
No
• P or B/W wire open,
or P wire shorted to
ground.
• Loose or poor
contacts on the ECM
coupler.
• If wire and
connection are OK,
replace the GP
switch with a new
one. Refer to "Gear
Position (GP) Switch
Removal and
Installation in Section
5B (Page 5B-13)".