C43 " " Oxygen Sensor Heater Circuit Malfunction - HYOSUNG MS3 250 Sercie Manual

4-33 FI SYSTEM DIAGNOSIS
"C43" OXYGEN SENSOR HEATER CIRCUIT MALFUNTION
DETECTED CONDITION
Oxygen sensor heater signal is not input in ECU.
▣ ▣ INSPECTION
1) Remove the right side front lower cover.
2) Turn the ignition switch "
3) Check the Oxygen sensor heater coupler for loose
or poor contacts.
If OK, then measure the Oxygen sensor heater
voltage.
4) Disconnect the coupler and then the ignition
switch " " (ON) position.
5) Measure the voltage between OB wire terminal
and B (or ground) wire terminal.
Oxygen sensor
heater voltage
Tester knob indication : Voltage (
Is the voltage OK?
● OB or B wire open or shorted to ground,
or poor �
● If wire and connection are OK,
YES
intermittent trouble or faulty ECU.
● Recheck each terminal and wire harness
for open circuit and poor connection.
NO Replace the Oxygen sensor.
" (OFF) position.
Battery voltage
( � OB - �
B )
( � OB - � Ground )
or �
connection.
● Oxygen sensor, Oxygen sensor heater circuit open
or short.
● Oxygen sensor, Oxygen sensor heater malfunction.
● ECU malfunction.
)
POSSIBLE CAUSE
�
ECU Coupler
�