Suzuki FL125S Service Manual page 349

"44" (P0130/P0135) HO2 SENSOR (HO2S) CIRCUIT MALFUNCTION
DETECTED CONDITION
44 HO2 sensor output voltage is not input
(P0130) to ECM during engine operation and
running condition.
(Sensor voltage < 0.60 V)
44 The heater can not operate so that
(P0135) heater operation voltage is not supply to
the oxygen heater circuit.
ECM
E2
HO2
HO2H
INSPECTION
Step 1 (When indicating 44/P0130:)
1) Turn the ignition switch OFF.
2) Remove the frame covers, left and right. (#5-7)
3) Check the HO2 sensor coupler 1 for loose or poor contacts.
If OK, then check the HO2 sensor lead wire continuity.
4) Disconnect the HO2 sensor coupler.
5) Check the continuity between W/G wire A and ground.
6) Also, check the continuity between W/G wire A and Br/B wire
B.
If the sound is not heard from the tester, the circuit condition is
OK.
$ 09900-25008: Multi-circuit tester set
* Tester knob indication: Continuity test ())
Br/B Br/B
W/G W/G
W W
Y/G Y/G
POSSIBLE CAUSE
• HO2 sensor circuit open or shorted to ground.
• Fuel system malfunction.
• ECM malfunction.
• HO2 sensor heater circuit open or shorted to
ground.
Battery
cut off
Ignition
switch relay
O O
HO2 sensor
1
1
FL125SDW 8-74
Fuse
(15A)
Battery