Function Explanation (DTC Detection Outline)
- The PCM detects the oxygen concentration passing through the catalyst by the HO2S signal and performs fuel injection amount correction to maintain optimum purification conditions in the catalyst. To maintain optimum purification conditions in the catalyst, the fuel injection correction has a [Feedback correction amount] which performs correction according to the driving conditions relative to the previously set air/fuel ratio, and a [Learning correction amount] which corrects for deterioration over time.
- [Fuel feedback correction amount [SHRT_FUEL_TRIM_HO2S_SEN]] and [Fuel learning correction amount [LONG_FUEL_TRIM_HO2S_SEN]] can be verified from the M-MDS PID item.
- If a condition in which the feedback correction amount from the HO2S signal is small (fuel injection amount being decreased) continues for the specified time (25 s), the PCM determines a feedback correction amount malfunction and stores a DTC.
- A condition in which the fuel feedback correction amount [SHRT_FUEL_TRIM_HO2S_SEN] for the HO2S is the specified value (?2 %) or less and the sum ([SHRT_FUEL_TRIM_HO2S_SEN]+[LONG_FUEL_TRIM_HO2S_SEN]) of the fuel feedback correction amount and the fuel learning correction amount is the specified value (?2.2 %) or less continues for a period of 25 s.
COMPONENT OPERATIONS
| Component no | Refer to |
|---|---|
| 1 | Correction amount (%) |
| 2 | 0 (%) |
| 3 | -2 (%) |
| 4 | -2.2 (%) |
| 5 | Fuel feedback correction amount [SHRT_FUEL_TRIM_HO2S_SEN] (normal) |
| 6 | Sum of fuel feedback correction amount and fuel learning correction amount ([SHRT_FUEL_TRIM_HO2S_SEN]+[LONG_FUEL_TRIM_HO2S_SEN]) (normal) |
| 7 | Fuel feedback correction amount [SHRT_FUEL_TRIM_HO2S_SEN] (abnormal) |
| 8 | Sum of fuel feedback correction amount and fuel learning correction amount ([SHRT_FUEL_TRIM_HO2S_SEN]+[LONG_FUEL_TRIM_HO2S_SEN]) (abnormal) |
| 9 | Specified period of time or more |
| 10 | Time |