4-74 FI SYSTEM DIAGNOSIS
• Voltage
09900-25008: Multi circuit tester set
Tester knob indication: Voltage (
)
– Between W, B or B/Br wires and ground: approx. 0 V
(When ignition switch is ON)
Is check result OK?
Step 3
HO2 sensor heater check
1) Measure the resistance between terminals.
NOTE:
* Temperature of the HO2 sensor affects resistance value
largely.
* Make sure that the HO2 sensor heater is in atmospheric tem-
perature.
09900-25008: Multi circuit tester set
Tester knob indication: Resistance (
)
HO2 sensor heater resistance:
6.7 – 9.5
at 23 °C (73 °F) (W – W)
Is check result OK?
YES
Go to Step 3.
NO
Repair or replace the defective wire harness.
V
2
YES
Go to Step 4.
NO
Replace the HO2 sensor with a new one.
(
4-93)
3
