Suzuki AN400 Service Manual page 128

1A-65 Engine General Information and Diagnosis:
Step
1 1) Turn the ignition switch OFF.
2) Check the HO2 sensor coupler (1) for loose or poor
contacts.
If OK, then measure the HO2 sensor output voltage.
3) Insert the needle pointed probe to the HO2 sensor lead
wire coupler.
4) Warm up the engine enough.
5) Measure the HO2 sensor output voltage between B/Y
wire and B/Br wire, when idling condition.
6) Measure the HO2 sensor output voltage while holding
the engine speed at 3 000 r/min.
HO2 sensor output voltage at idle speed
0.3 V and less
(Positive terminal: B/Y – Negative terminal: B/Br)
HO2 sensor output voltage at 3 000 r/min
0.7 V and more
(Positive terminal: B/Y – Negative terminal: B/Br)
Special tool
(A): 09900–25008 (Multi-circuit tester set)
(B): 09900–25009 (Needle pointed probe set)
Tester knob indication
Voltage ( )
Is the voltage OK?
Action
1
B/Br
(A)
V
(B)
B/Y
Yes
Go to Step 2.
I705H1110104-04
I705H1110107-04
No
Replace the HO2
sensor with a new one.