Circuit Description
The front oxygen sensor is used to monitor oxygen concentration in the exhaust. For optimum catalytic converter operation, the air fuel mixture must be maintained near the ideal "stoichiometric" ratio. The heated oxygen sensor output voltage changes suddenly at the stoichiometric ratio. The ECM adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric.
When the air-fuel ratio becomes LEAN, the oxygen concentration in the exhaust gas increases. And the heated oxygen sensor informs the ECM of the LEAN condition (low voltage, i.e. less than 0.45 V).
When the air-fuel ratio is RICHER than the stoichiometric air-fuel ratio, the oxygen will be vanished from the exhaust gas. And the heated oxygen sensor informs the ECM of the RICH condition (high voltage, i.e.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0130 | Output Voltage Of Heated Oxygen Sensor Remains At 0.4 V Or More, Or 0.55 V Or Less, During Idling After Engine Is Warmed Up (2 Trip Detection Logic) |
|
| P2195 | Output Voltage Of Heated Oxygen Sensor Remains At 0.55 V Or Less, During Idling After Engine Is Warmed Up (2 Trip Detection Logic) | |
| P2196 | Output Voltage Of Heated Oxygen Sensor Remains At 0.4 V Or More, During Idling After Engine Is Warmed Up (2 Trip Detection Logic) |
- Sensor 1 refers to the sensor closest to the engine body.
- The output voltage of the heated oxygen sensor and the short-term fuel trim value can be read using the hand-held tester or the OBD II scan tool.