Suzuki AN400 Service Manual page 171

Step 2
1) Turn the ignition switch OFF.
2) Turn the ignition switch ON and measure the heater
voltage between O/W wire (ECM side) and ground.
3) If the tester voltage indicates the battery voltage for few
seconds, it is good condition.
$ Heater voltage: Battery voltage
NOTE:
Battery voltage can be detected only during few seconds after
ignition switch is turned ON.
! 09900-25008: Multi circuit tester set
& Tester knob indication: Voltage (')
Is the voltage OK?
YES Go to Step 3
NO Replace the HO2 sensor with a new one.
Step 3
1) Turn the ignition switch OFF.
2) Disconnect the HO2 sensor coupler.
3) Check the resistance between the terminals (White –
White) of the HO2 sensor.
$ HO2 heater resistance: 11.5 – 14.5 Ω Ω Ω Ω (at 23 °C/73.4 °F)
NOTE:
* Temperature of the sensor affects resistance value largely.
* Make sure that the sensor heater is at correct temperature.
! 09900-25008: Multi circuit tester set
% Tester knob indication: Resistance (Ω Ω Ω Ω )
Is the resistance OK?
• Black, Gray or White wire open or shorted to
ground, or poor A, E, K or P connection.
• If wire and connection are OK, intermittent trou-
YES
ble or faulty ECM.
• Recheck each terminal and wire harness for
open circuit and poor connection.
NO Replace the HO2 sensor with a new one.
(O/W – Ground)
(White – White)
FI SYSTEM 4-43
ECM Coupler