ENGINE GENERAL INFORMATION AND DIAGNOSIS (M13 ENGINE) 6-2-105
Troubleshooting
Step Action Yes No
1Was “Engine and Emission Control System
Check” performed?
Go to Step 2. Go to “Engine and Emis-
sion Control System
Check” in this section.
2Check HO2S–2 heater power circuit.
1) Disconnect connector from HO2S–2 sen-
sor with ignition switch turned OFF.
2) Check for proper connection to HO2S–2
sensor at “BLK/WHT” and “BLU/RED” wire
terminals.
3) If wire and connection are OK, measure
voltage between “BLK/WHT” wire terminal
of HO2S–2 sensor connector and engine
ground with ignition switch turned ON.
Is voltage over 10 V?
Go to Step 3. “BLK/WHT” wire open cir-
cuit or shorted to ground
circuit.
3Check HO2S–2 heater power circuit.
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Measure resistance between “BLK/WHT”
wire terminal of HO2S–2 sensor connector
and “E21-28” terminal wire of ECM connec-
tor.
Is resistance below 5
Ω
?
Go to Step 4. “BLK/WHT” wire high
resistance circuit.
4Check HO2S–2 heater drive circuit.
1) Measure resistance between “BLU/RED”
wire terminal of HO2S–2 sensor connector
and vehicle body ground.
Is resistance infinity?
Go to Step 5. “BLU/RED” wire shorted
to ground circuit.
5Check HO2S–2 heater drive circuit.
1) Turn ON ignition switch.
2) Measure voltage between “BLU/RED” wire
terminal of HO2S–2 sensor connector and
vehicle body ground.
Is voltage 0 V?
Go to Step 6. “BLU/RED” wire shorted
to power circuit.
6Check HO2S–2 heater drive circuit.
1) Connect connector to HO2S–2 with ignition
switch turned OFF.
2) Turn ON ignition switch.
3) Measure voltage between “E23-3” wire ter-
minal of disconnected ECM connector and
vehicle body ground.
Is voltage over 10 V?
Go to Step 7. “BLU/RED” wire open cir-
cuit.
7 Check heater of sensor–2.
1) Disconnect HO2S–2 coupler with ignition
switch turned OFF.
2) If OK, then check heater resistance.
Is it 11.7 – 14.3
Ω
at 20°C, 68°F?
Go to Step 8. Replace HO2S–2.
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