P0091

The P0091 code indicates a fuel pressure regulator 1 control circuit low condition has been detected by the vehicle's powertrain control module (PCM). This code relates to the fuel delivery and metering system, which is responsible for providing the correct amount of fuel to the engine. When this code is stored, the fuel system is not operating within the expected parameters, which can affect engine performance and fuel economy. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Engine stalling or rough idle. Difficulty starting the engine. Check Engine Light (MIL) illuminated. Loss of power during driving. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Contaminated fuel. Faulty fuel volume regulator control solenoid. Clogged or dirty fuel filter. Wiring issues in the fuel system circuit. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Connect an OBD-II scanner and read all stored trouble codes and freeze frame data. Check fuel pressure using a fuel pressure gauge; compare to manufacturer specifications. Inspect fuel lines, connections, and injectors for leaks or damage. Test the fuel pressure regulator for proper operation. Check the fuel pump relay and electrical connections. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Powertrain (P) collection on OBD Codes. We provide comprehensive, up-to-date information to help you find solutions quickly.