4-78 FI SYSTEM DIAGNOSIS
6) Measure the HO2 sensor output voltage while holding the
engine speed at 5 000 r/min.
HO2 sensor output voltage at 5 000 r/min:
0.6 V or more
(
+
terminal: B –
-
terminal: B/Br)
Is check result OK?
P0135 for HO2 sensor (Use of SDS)
Step 1
HO2 sensor heater power supply circuit check
1) Turn the ignition switch OFF.
2) Disconnect the HO2 sensor coupler
1
. (
4-93)
3) Check for proper terminal connection to the HO2 sensor cou-
pler.
4) If connections are OK, turn the ignition switch ON.
5) Measure the voltage between O/W wire and ground.
09900-25008: Multi circuit tester set
Tester knob indication: Voltage (
)
HO2 sensor heater power supply voltage:
Battery voltage
(
+
terminal: O/W –
-
terminal: Ground)
Is check result OK?
YES
Replace the ECM with a known good one, and
inspect it again.
NO
Replace the HO2 sensor with a new one.
(
4-93)
2
1
YES
Go to Step 2.
NO
Repair or replace the O/W wire.
1
