DTC Detection Logic
The Heated Oxygen Sensor 2 has a much longer Switching time between rich and lean than the air fuel ratio (A/F) Sensor 1. The Oxygen storage capacity of the three way catalyst 1 causes the longer Switching time.
MALFUNCTION A
To judge malfunctions of Heated Oxygen Sensor 2, ECM monitors whether the voltage is unusually high during various driving conditions such as fuel cut.
MALFUNCTION B
To judge malfunctions of Heated Oxygen Sensor 2, ECM monitors whether the minimum voltage of Sensor is sufficiently low during various driving conditions such as fuel cut.
| DTC No. | Trouble Diagnosis Name | DTC Detecting Condition | Possible Cause | |
|---|---|---|---|---|
| P0138 | Heated Oxygen Sensor 2 (Bank 1) Circuit high voltage | A) | An excessively high voltage from the Sensor is sent to ECM. |
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| B) | The minimum voltage from the Sensor is not reached to the specified voltage. |
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| P0158 | Heated Oxygen Sensor 2 (Bank 2) Circuit high voltage | A) | An excessively high voltage from the Sensor is sent to ECM. |
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| B) | The minimum voltage from the Sensor is not reached to the specified voltage. |
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