PowertrainP0401
CautionSeverity: Caution - get it checked when you can
Exhaust Gas Recirculation Flow Insufficient Detected
Key terms: EGR: exhaust gas recirculation, which cuts harmful gases · SAE J2012: the standard generic code list · Powertrain: engine, transmission and emissions
1What it means in plain English
The exhaust gas recirculation (EGR) system is flowing less exhaust gas than the engine computer expects, usually because of carbon build-up.
2Common causes
- Clogged EGR passages or valve
- Faulty EGR valve
- Leaking or blocked EGR pipe
- Faulty EGR position sensor
- Carbon build-up in the intake manifold
3Can I drive?
Usually safe to drive. Rough idling, pinging, or failed emissions tests can follow; have it checked before an inspection.
This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.
4Brand data 41
| Brand | Code | Description | System |
|---|---|---|---|
| Ashok Leyland CV | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected SAE | Powertrain |
| BAIC Motor | P0401 | Exhausted Gas Recirculation (EGR) flow too low Brand | Powertrain |
| Mercedes-Benz | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected SAE | Powertrain |
| BMW | P0401 | Exhaust Gas Recirculation Insufficient Detected Brand | Powertrain |
| BYD | P0401 | EGR flow insufficient Brand | Powertrain |
| Chery | P0401 | EGR flow insufficient Brand | Powertrain |
| Chrysler | P0401 | Implausible Data Received From ECM/PCM Brand | Powertrain |
| Daewoo | P0401 | Exhaust Gas Recirculation Valve Stuck Brand | Powertrain |
| Daihatsu | P0401 | EGR function failed Brand | Powertrain |
| DFFS | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected Brand | Powertrain |
| DFFX | P0401 | EGR flow insufficient Brand | Powertrain |
| DFXK | P0401 | EGR flow insufficient Brand | Powertrain |
| EOBD | P0401 | Zaznana nezadostna pretok EGR 'A' Brand | Powertrain |
| Fiat | P0401 | Implausible data received from ECM/PCM Brand | Powertrain |
| Ford | P0401 | MIL ON, DTC Brand | Powertrain |
| Geely | P0401 | EGR Flow Insufficient Brand | Powertrain |
| GM | P0401 | Exhaust Gas Recirculation(EGR) Flow Insufficient Brand | Powertrain |
| Great Wall | P0401 | EGR flow insufficient Brand | Powertrain |
| Hafei | P0401 | EGR flow insufficient Brand | Powertrain |
| Holden | P0401 | Exhaust Gas Recirculation (EGR) Flow Incorrect Brand | Powertrain |
| Honda | P0401 | NOTE: If the monitor of is not executed in this drive cycle, this parameter will show "0%" Brand | Powertrain |
| Hyundai | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected SAE | Powertrain |
| Isuzu | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected SAE | Powertrain |
| Land Rover | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected SAE | Powertrain |
| Maserati | P0401 | Exhaust Gas Recirculation (EGR) System Performance Brand | Powertrain |
| Mazda | P0401 | MIL ON, DTC Brand | Powertrain |
| Mitsubishi | P0401 | EGR flow Insufficient Brand | Powertrain |
| Nissan | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected SAE | Powertrain |
| Opel | P0401 | Exhaust Gas Recirculation(EGR) Flow Insufficient Brand | Powertrain |
| Perodua | P0401 | EGR function failed Brand | Powertrain |
| Peugeot | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected SAE | Powertrain |
| Porsche | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected SAE | Powertrain |
| Proton | P0401 | EGR flow Insufficient Brand | Powertrain |
| Saab | P0401 | Abgasrückführung (EGR) unzureichende Flussrate Brand | Powertrain |
| MG (SAIC) | P0401 | Passenger airbag Leakage to plus on squib Brand | Powertrain |
| Subaru | P0401 | Exhaust Gas Recirculation Flow Insufficient Detected SAE | Powertrain |
| Suzuki | P0401 | Exhaust Gas Recirculation 'A' Flow Insufficient Detected Brand | Powertrain |
| SWM Motor | P0401 | EGR flow is insufficient Brand | Powertrain |
| Tata | P0401 | EGR Valve Blocked Closed Brand | Powertrain |
| Toyota | P0401 | Switch, key or wiring harness failure (degraded start) Brand | Powertrain |
| Volkswagen | P0401 | EGR system: insufficient flow; Short to ground Brand | Powertrain |
Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.
5Extended variant codes 2
These 7-character codes are manufacturer-specific variants of P0401 and may be reported by some scan tools.
6Related codes
Browse Pxxx codes or P040xx codes.