P1391 on TOYOTA PRIUS — Glow Plug Circuit Low Input (Bank #1)

Q: "What does P1391 mean on a TOYOTA PRIUS?"

"P1391 indicates: Glow Plug Circuit Low Input (Bank #1). This is a manufacturer-specific powertrain code. 2 TOYOTA PRIUS owners have reported this to NHTSA."

Q: "What are the most common causes of P1391 on TOYOTA PRIUS?"

"Based on 2 NHTSA reports, the most commonly cited components are: Electronic Stability Control (Esc),Service Brakes, Service Brakes. These percentages are based on the component field in owner complaints."

Q: "Is P1391 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 P1391?"

"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 P1391 Means on Your TOYOTA PRIUS

P1391 is a diagnostic trouble code indicating: Glow Plug Circuit Low Input (Bank #1). This code relates to the manufacturer-specific powertrain 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 2010-2012. Most reports come from the 2010, 2012 model years. The most commonly reported component is Electronic Stability Control (Esc),Service Brakes (50.0% of reports).

Real TOYOTA PRIUS Owner Reports

Source: NHTSA Complaints Database

"I brought my toyota prius to toyota dealer as abs alert was on and i lost controlling the brake. toyota dealer gave me an estimate for repair at $2,850."

— 2010 TOYOTA PRIUS owner · ELECTRONIC STABILITY CONTROL (ESC),SERVICE BRAKES · Filed 06/01/2020

"During a hard braking, felt brake pedal softer and less responsive braking. Now ABS Icon, Brake Icon, and Traction Icon is on. Confirmed Code P1391 in ABS system."

— 2012 TOYOTA PRIUS owner · SERVICE BRAKES · Filed 10/21/2022

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

📊 Complaint Trend by Model Year

1

'10

1

'12

Common Causes on TOYOTA PRIUS

Based on NHTSA complaint component analysis for this vehicle.

ELECTRONIC STABILITY CONTROL (ESC),SERVICE BRAKES 50%

SERVICE BRAKES 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 P1391 mean on a TOYOTA PRIUS? ▾

P1391 indicates: Glow Plug Circuit Low Input (Bank #1). This is a manufacturer-specific powertrain code. 2 TOYOTA PRIUS owners have reported this to NHTSA.

What are the most common causes of P1391 on TOYOTA PRIUS? ▾

Based on 2 NHTSA reports, the most commonly cited components are: Electronic Stability Control (Esc),Service Brakes, Service Brakes. These percentages are based on the component field in owner complaints.

Is P1391 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 P1391? ▾

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.

P1391 on Other Vehicles

→ All codes reported on TOYOTA PRIUS