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P0090 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


The particular DTC referred to as a “fuel pressure regulator 1 control circuit” is P0090. If an engine control module has detected a malfunction or abnormally high voltage in the Fuel Pressure Controller 1 circuit, this code will be activated.


The maintenance of the proper fuel pressure in the fuel system shall be entrusted to the Fuel Pressure Regulator. The improper regulation of fuel pressure can have a negative effect on engine performance and fuel efficiency if the ECM discovers an irregularity in the control circuit.


  • A faulty fuel pressure regulator may damage the control circuit, which could result in a P0090 code. 
  • Wiring or Connector Problem: Communication problems with the electronic control unit may result from damaged or defective wires, connectors, and terminals connected to the fuel pressure regulator circuit. 
  • ECM Malfunction: A malfunctioning Engine Control Module itself could falsely trigger the P0090 code.


  • Check Engine Light: The illumination of the check engine light on the vehicle’s dashboard is one of the major symptoms of the P0090 code. 
  • Lack of engine performance: The vehicle may have difficulty at idle, hesitation in acceleration, or a lack of power. 
  • Decrease in fuel efficiency: excessive fuel delivery and reduced fuel economy may result from a failure in the control circuit for the pressure regulator.


The P0090 code has to be diagnosed using a methodical process:

  • OBD-II Scanner: A skilled mechanic will access the exact code and any associated codes recorded in the ECM using an OBD-II scanner.
  • Visual check: The fuel pressure regulator, along with any related wiring and connectors, will undergo a comprehensive visual check by the mechanic.
  • Check for Voltage and Ground: Using a multimeter, the technician will make sure that the fuel pressure regulator control circuit has the correct voltage and ground signals.

Common mistakes

  • Failure to check electrical wire and connector: Sometimes the primary cause is compromised or damaged wiring, which has been rarely taken into consideration in diagnosis. 
  • Neglecting related codes: In order to determine the true cause of the problem, other related codes may provide important information.

How serious is this?

The underlying reason for the P0090 code, as well as how it affects the fuel system and engine performance, determine the code’s significance. Ignoring the problem might result in subpar engine operation, lower fuel economy, and possibly even damage to other parts.

What repairs can fix the code?

repair manuals

  • Replace the Fuel Pressure Regulator: To guarantee correct fuel pressure regulation, the fuel pressure regulator should be changed if it is determined to be defective.
  • Repair or Replace Wiring and Connectors: In order to reestablish effective communication between the fuel pressure regulator and ECM, damaged or corroded wiring and connectors should be fixed or replaced.
  • Examine and fix ECM problems: If an ECM fault is the source of the P0090 code, the ECM may need to be repaired or reprogrammed.

Related codes

  • P0087 (Fuel Rail/System Pressure – Too Low): This code indicates low fuel pressure, which may be related to the P0090 issue.


The DTC code P0090 indicates that there may be a potential problem in the fuel pressure regulator control circuit, which could have an impact on the correct setting of pressures within the Fuel System. It is necessary that you have a qualified vehicle technician diagnose and solve the problem as soon as possible in the case of this code.

It is vital to make the repairs as soon as possible so that your vehicle’s engine performance, fuel efficiency, and total system health can be maintained. Failure to address the issue might result in more complex complications and an increased cost of fixing it.

P0090 Code – What Does It Mean & How To Fix It