What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P0401Exhaust Gas Recirculation Flow Insufficient DetectedP0401Exhaust Gas Recirculation Flow insufficient DetectedP0401EXHAUST GAS RECIRCULATION FLOW INSUFFICIENT DETECTEDManufacturer communications
16Original wording in English
TOYOTA
Reported code forms P0401
Warranty Enhancement Program: Toyota has received reports of a rough idle and/or rattle noise from the transaxle at cold start due to a sticking Exhaust Gas Recirculation (EGR) Valve in some vehicles. If this occurs,…
TOYOTA
Reported code forms P0401
Warranty Policy Bulletin (POL16-04): Toyota has received reports of a rough idle and/or rattle noise from the transaxle at cold start due to a sticking Exhaust Gas Recirculation (EGR) Valve in some vehicles. If this…
TOYOTA
Reported code forms P0401
Warranty Policy Bulletin (POL16-04): In these vehicles, Toyota has received some reports of a rough idle and/or rattle noise from the transaxle at cold start due to a sticking Exhaust Gas Recirculation (EGR) Valve. If…
TOYOTA
Reported code forms P0401
Dealer Letter: In these vehicles, Toyota has received some reports of a rough idle and/or rattle noise from the transaxle at cold start due to a sticking Exhaust Gas Recirculation (EGR) Valve. If this occurs, the…
TOYOTA
Reported code forms P0401
Dealer email: In these vehicles, Toyota has received some reports of a rough idle and/or rattle noise from the transaxle at cold start due to a sticking Exhaust Gas Recirculation (EGR) Valve. If this occurs, the vehicle…
TOYOTA
Reported code forms P0401
WARRANTY POLICY BULLETIN (POL16-04): IN THESE VEHICLES, TOYOTA HAS RECEIVED SOME REPORTS OF A ROUGH IDLE AND/OR RATTLE NOISE FROM THE TRANSAXLE AT COLD START DUE TO A STICKING EXHAUST GAS RECIRCULATION (EGR) VALVE. IF…
Check vehicle applicability
1A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Toyota | PRIUS | 2012 |
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.