DTC P0401 [L3]: Notes
DTC P0401 (L3) DETECTION CONDITION & POSSIBLE CAUSES
| DTC P0401 |
EGR flow insufficient detected |
| DETECTION CONDITION |
- PCM monitors difference in intake manifold pressures when EGR is operated and when it is stopped. If the difference is too small, PCM determines that EGR flow insufficient.
MONITORING CONDITION
- EGR system-Repair Verification Drive Mode.
- Following conditions are met
- Engine speed: 1,600-3,000 rpm [MTX]/1,600-3,250 rpm [ATX]
- Throttle position: 2.8-11.8%(at engine speed is 2,500 rpm)
- Absolute load: 22-45%
- Vehicle speed: above 70 km/h {43.2 mph}
- Target of EGR position (stepping motor): above 24 steps
Diagnostic support note
- This is an intermittent monitor (EGR system).
- MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
- PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
- FREEZE FRAME DATA is available.
- DTC is stored in the PCM memory.
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| POSSIBLE CAUSE |
- Clogs, damage, frozen or leakage in vacuum hose
- EGR valve malfunction
- MAP sensor malfunction
- EGR gasket malfunction
- PCM malfunction
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