Suzuki GSX-R750 Service Manual page 183

Step
2 1) Connect the HO2 sensor coupler.
2) Insert the needle pointed probes to the lead wire coupler.
3) Turn the ignition switch ON and measure the heater
voltage between the W/B wire and ground.
If the tester voltage indicates the battery voltage, it is
good condition.
NOTE
Battery voltage can be detected only before
starting the engine.
Special tool
(A): 09900–25008 (Multi-circuit tester set)
(B): 09900–25009 (Needle pointed probe set)
Tester knob indication
Voltage ( )
Heater voltage
Battery voltage
((+) terminal: W/B – (–) terminal: Ground)
Is the voltage OK?
Action
(A)
(B)
I837H1110150-02
Engine General Information and Diagnosis:
Yes
• O/W or W/B wire
open or shorted to
ground, or poor "41"
connection.
• Recheck each
terminal and wire
harness for open
circuit and poor
connection.
• If wire and
connection are OK,
intermittent trouble or
faulty ECM.
• Replace the ECM
with a known good
one, and inspect it
again. Refer to "ECM
Removal and
Installation in Section
1C (Page 1C-1)".
1A-111
No
• Open or short circuit
in the W/B wire or O/
W wire.
• Loose or poor
contacts on the ECM
coupler or HO2
sensor coupler.