DTC Detection Logic
WARNING: This page is about a different car, the 2016 Infiniti QX60. However, it is still accessible from the selected car via links, so may be relevant.
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 (manifold) causes the longer switching time.
MALFUNCTION A
To judge the malfunctions of heated oxygen sensor 2, ECM monitors whether the voltage is unusually high during various driving conditions such as fuel cut.
| : 1.3 V |
MALFUNCTION B
To judge the 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. | CONSULT screen terms (Trouble diagnosis content) |
DTC detecting condition | Possible cause | |
|---|---|---|---|---|
| P0138 | HO2S2 (B1) (O2 sensor circuit high voltage bank 1 sensor 2) |
A) | An excessively high voltage from the sensor is sent to ECM. |
|
| B) | The minimum voltage from the sensor is not reached to the specified voltage. |
|
||
| P0158 | HO2S2 (B2) (O2 sensor circuit high voltage bank 2 sensor2) |
A) | An excessively high voltage from the sensor is sent to ECM. |
|
| B) | The minimum voltage from the sensor is not reached to the specified voltage. |
|
||