DTC P0421:00: Notes
DTC P0421:00 (LF, L5) DETECTION CONDITION AND POSSIBLE CAUSE
| DTC P0421:00 |
Warm up catalyst system efficiency below threshold |
| DETECTION CONDITION |
- The PCM compares the number of A/F sensor and HO2S inversions for a predetermined time. The PCM monitors the HO2S inversion counts when the following conditions are met. The PCM detects inversion ratio. If the inversion ratio is below specification, the PCM determine that catalyst system has deteriorated.
- The A/F sensor inversion counts is as prescribed when the following monitoring conditions are met:
- The accumulated occurrence time of the following monitoring conditions has exceeded the prescribed time limit:
MONITORING CONDITIONS
- Catalyst converter temperature: more than 400 °C {752 °F}
- Engine speed:
- 1,350-3,000 rpm
(LF/ATX)
- 1,500-3,000 rpm
(LF/MTX)
- 1,200-3,000 rpm
(L5/ATX)
- 1,300-3,000 rpm
(L5/MTX)
- Charging efficiency: 15-48%
(engine speed: 2,000 rpm
)
Diagnostic support note
- This is an intermittent monitor (catalyst).
- The MIL illuminates if PCM detects above malfunction condition in two consecutive drive cycles or in one
- drive cycle while DTC for the same malfunction has been stored in PCM.
- PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.
- FREEZE FRAME DATA (Mode 2)/Snapshot data is available.
- The DTC is stored in the PCM memory.
|
| POSSIBLE CAUSE |
- Leakage exhaust system
- Looseness A/F sensor
- Looseness HO2S TWC malfunction
- PCM malfunction
|