Suzuki GSX-R750 Service Manual page 208

1A-136 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 speed sensor coupler (1) for loose or poor
contacts.
If OK, remove the speed sensor. Refer to "Speed Sensor
Removal and Installation in Section 9C (Page 9C-5)".
4) Connect 12 V battery, 10 kΩ resistor and the multi-circuit
tester as shown in the figure.
Special tool
: 09900–25008 (Multi-circuit tester set)
Tester knob indication
Voltage ( )
Action
1
I837H1110117-01
12 V
B/W
B
B/R
Speed sensor
I837H1110118-01
Yes
• P wire open or
shorted to ground.
• Loose or poor
contacts on the
speed sensor coupler
or ECM coupler
(terminal "2").
• If wires 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.
No
• Inspect that metal
particles or foreign
material stuck on the
speed sensor and
rotor tip.
• If there are no metal
particles and foreign
material, then replace
the speed sensor
with a new one.