P0401 on TOYOTA PRIUS — EGR A Flow Insufficient Detected

Q: "What does P0401 mean on a TOYOTA PRIUS?"

"P0401 indicates: EGR A Flow Insufficient Detected. This is a emission controls code. 2 TOYOTA PRIUS owners have reported this to NHTSA."

Q: "What are the most common causes of P0401 on TOYOTA PRIUS?"

"Based on 2 NHTSA reports, the most commonly cited components are: Unknown Or Other,Engine,Fuel/Propulsion System, Power Train. These percentages are based on the component field in owner complaints."

Q: "Is P0401 serious on my TOYOTA PRIUS?"

"Of 2 NHTSA reports for this code on TOYOTA PRIUS, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic."

Q: "What should I do if my TOYOTA PRIUS shows P0401?"

"1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare."

What P0401 Means on Your TOYOTA PRIUS

P0401 is a diagnostic trouble code indicating: EGR A Flow Insufficient Detected. This code relates to the emission controls system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

2 TOYOTA PRIUS owners have reported this issue to NHTSA across model years 2010. Most reports come from the 2010 model year. The most commonly reported component is Unknown Or Other,Engine,Fuel/Propulsion System (50.0% of reports).

Real TOYOTA PRIUS Owner Reports

Source: NHTSA Complaints Database

"Vehicle has lost power on the freeway multiple times forcing me to pull over. in one instance i was almost rear ended by a semi. the vehicle will show a temperature warning and will then shut down and read, "check hybrid system". the toyota dealership claims it needs a new engine."

— 2010 TOYOTA PRIUS owner · UNKNOWN OR OTHER,ENGINE,FUEL/PROPULSION SYSTEM · Filed 08/13/2018

"My 2010 toyota prius iv has 98,731 miles on it. the engine and power train malfunctioned during a cold start so i had to take it into the toyota dealer."

— 2010 TOYOTA PRIUS owner · POWER TRAIN · Filed 01/22/2017

All reports filed by vehicle owners directly with the U.S. Department of Transportation.

📊 Complaint Trend by Model Year

2

'10

Common Causes on TOYOTA PRIUS

Based on NHTSA complaint component analysis for this vehicle.

UNKNOWN or OTHER,ENGINE,FUEL/PROPULSION SYSTEM 50%

POWER TRAIN 50%

What To Do Next

1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.

Frequently Asked Questions

What does P0401 mean on a TOYOTA PRIUS? ▾

P0401 indicates: EGR A Flow Insufficient Detected. This is a emission controls code. 2 TOYOTA PRIUS owners have reported this to NHTSA.

What are the most common causes of P0401 on TOYOTA PRIUS? ▾

Based on 2 NHTSA reports, the most commonly cited components are: Unknown Or Other,Engine,Fuel/Propulsion System, Power Train. These percentages are based on the component field in owner complaints.

Is P0401 serious on my TOYOTA PRIUS? ▾

Of 2 NHTSA reports for this code on TOYOTA PRIUS, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic.

What should I do if my TOYOTA PRIUS shows P0401? ▾

1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare.

P0401 on Other Vehicles

VOLKSWAGEN JETTA

3 reports

→ All codes reported on TOYOTA PRIUS