DTC detecting condition | Trouble area |
---|---|
Current of HO2S-1 heater is more than specified value or lower than specified value for 5 seconds continuously.
(2 driving cycle detection logic) |
•
HO2S-1 heater circuit
• HO2S-1 heater • ECM |
Step | Action | YES | NO |
---|---|---|---|
1 |
Was “Engine and Emission Control System Check” performed?
|
Go to Step 2.
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|
2 |
HO2S-1 heater power circuit check
1)
Disconnect connector from HO2S-1 with ignition switch turned OFF.
2)
Check for proper connection to HO2S-1 at “BLK/WHT” and “PNK/BLK” wire terminals.
3)
If wire and connection are OK, measure voltage between “BLK/WHT” wire terminal and engine ground with ignition switch turned ON.
Is voltage over 10 V?
|
Go to Step 3.
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“BLK/WHT” wire is open circuit or shorted to ground circuit.
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3 |
HO2S-1 heater power circuit check
1)
Disconnect connectors from ECM with ignition switch turned OFF.
2)
Measure resistance between “BLK/WHT” wire terminal of HO2S-1 connector and “E118-28” terminal of ECM connector.
Is resistance below 5 Ω?
|
Go to Step 4.
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“BLK/WHT” wire high resistance circuit.
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4 |
HO2S-1 heater drive circuit check
1)
Measure resistance between “E117-4” terminal of ECM connector and vehicle body ground.
Is resistance infinity?
|
Go to Step 5.
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“PNK/BLK” wire shorted to ground circuit.
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5 |
HO2S-1 heater drive circuit check
1)
Turn ON ignition switch.
2)
Measure voltage between “E117-4” terminal of ECM connector and vehicle body ground.
Is voltage 0 V?
|
Go to Step 6.
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“PNK/BLK” wire shorted to power circuit.
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6 |
HO2S-1 heater drive circuit check
1)
Connect connector to HO2S-1 with ignition switch turned OFF.
2)
Turn ON ignition switch.
3)
Measure voltage between “E117-4” terminal of ECM connector and vehicle body ground with disconnect connector from ECM.
Is voltage over 10 V?
|
Go to Step 7.
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“PNK/BLK” wire open circuit.
|
7 |
HO2S-1 heater check
1)
Disconnect HO2S-1 coupler with ignition switch turned OFF.
2)
Check HO2S-1 heater resistance referring to
Heated Oxygen Sensor (HO2S-1 and HO2S-2) Heater On-Vehicle Inspection:M13A
.
Is resistance within specified value?
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Go to Step 8.
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Replace HO2S-1.
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8 |
HO2S-1 heater power circuit check
1)
Connect connector to HO2S-1 with ignition switch turned OFF.
2)
Measure resistance between “E118-28” and “E117-4” terminals of ECM connector.
Is resistance below 12 Ω?
|
HO2S-1 heater circuit are OK.
Substitute a known-good ECM and recheck.
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“BLK/WHT”, “PNK/BLK” and/or “BLK” wire high resistance circuit.
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