AutoCodes – Toyota – P0191 Toyota

P0191 Toyota Code - Fuel Rail Pressure Sensor Circuit Range / Performance

Quick Answer

With a cold engine, the internal pressure of the common rail is regulated by the Pressure Control Valve of the common rail assembly. Common causes include Faulty Fuel Rail Pressure Sensor, Fuel Rail Pressure Sensor harness is open or shorted, Fuel Rail Pressure Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0191 Toyota indicates Fuel Rail Pressure Sensor Circuit Range / Performance.
Common causes: Common causes include Faulty Fuel Rail Pressure Sensor, Fuel Rail Pressure Sensor harness is open or shorted, Fuel Rail Pressure Sensor circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 13,112

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 26, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0191 Toyota Description

With a cold engine, the internal pressure of the common rail is regulated by the Pressure Control Valve of the common rail assembly. With a warm engine, it is regulated by the suction control valve of the fuel supply pump. When the engine is running with a light load, it is regulated by both the pressure control valve and the suction control valve. Based on signals from the Engine Control Module (ECM), the pressure control valve opens when sudden deceleration occurs to prevent the fuel pressure from becoming too high. The Diagnostic Trouble Code (DTC) will set when the Engine Control Module has determined that the fuel rail pressure is not to factory specifications.

OBDII Code P0191 Toyota - Fuel Rail Pressure Sensor Circuit Range / Performance - AutoCodes.com — P0191 Toyota Code - Fuel Rail Pressure Sensor Circuit Range / Performance

What does this mean?

What are the Possible Causes of the DTC P0191 Toyota?

Faulty Fuel Rail Pressure Sensor
Fuel Rail Pressure Sensor harness is open or shorted
Fuel Rail Pressure Sensor circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0191 Toyota?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0191 Toyota code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Need more information on how to fix the P0191 Toyota code? Get Access to Factory Service Manuals

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Get the P0191 Toyota code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0191 Toyota Code

1. What are common symptoms of OBDII code P0191 in a Toyota?

- Common symptoms include rough idling, loss of power, engine misfires, poor fuel efficiency, and the illumination of the Check Engine Light.

2. What causes the OBDII code P0191 in a Toyota?

- The code P0191 in a Toyota is typically caused by a faulty fuel rail pressure sensor, issues with the fuel system, wiring problems, or a problem with the engine control module (ECM).

3. How can I diagnose the OBDII code P0191 in my Toyota?

- Diagnosing the code involves using a scan tool to read the code, checking the fuel pressure with a gauge, inspecting the fuel rail pressure sensor and its wiring, and verifying the fuel system components for proper functionality.

4. Can a dirty fuel filter trigger the OBDII code P0191 in a Toyota?

- Yes, a clogged or dirty fuel filter can cause a drop in fuel pressure, which can trigger the P0191 code by causing the fuel rail pressure sensor to detect a performance issue.

5. What are some repair tips for fixing the OBDII code P0191 in a Toyota?

- Repair tips include replacing the fuel rail pressure sensor, inspecting and repairing any damaged wiring, cleaning or replacing the fuel filter, checking the fuel pump for proper operation, and resetting the ECM after repairs.

6. Is it safe to continue driving with the OBDII code P0191 illuminated in a Toyota?

- It is not recommended to continue driving with the P0191 code illuminated, as it can lead to more serious engine issues and potential damage if left unresolved.

7. Can a DIY enthusiast fix the OBDII code P0191 in a Toyota?

- While some aspects of diagnosing and repairing the P0191 code can be done by a DIY enthusiast, it is recommended to seek professional help, especially when dealing with fuel system components and electrical issues.

8. How much does it typically cost to repair the OBDII code P0191 in a Toyota?

- The cost of repairing the P0191 code in a Toyota can vary depending on the root cause, but it can range from $100 to $500 for parts and labor, excluding diagnostic fees.

9. Will resetting the Check Engine Light resolve the OBDII code P0191 in a Toyota?

- Resetting the Check Engine Light may temporarily turn off the light, but it will not fix the underlying issue causing the P0191 code. Proper diagnosis and repairs are necessary to resolve the problem.

10. Can extreme weather conditions affect the occurrence of the OBDII code P0191 in a Toyota?

- Yes, extreme weather conditions such as extreme cold or heat can affect fuel pressure and the performance of the fuel system components, potentially leading to the triggering of the P0191 code.