p0091 fuel pressure regulator control circuit low
P0091 – Fuel Pressure Regulator Control Circuit Low
Description: This code indicates that the powertrain control module (PCM) has detected a low voltage condition in the fuel pressure regulator control circuit.
Definition: The P0091 code is triggered when the PCM detects an issue with the electrical circuit controlling the fuel pressure regulator, specifically indicating that the voltage is lower than expected. This can affect fuel delivery and engine performance.
P0091 – Fuel Pressure Regulator Control Circuit Low
Typical Severity: Moderate
Common Causes
P0091 – Fuel Pressure Regulator Control Circuit Low
Common causes:
- Faulty fuel pressure regulator
- Clogged fuel filter
- Fuel pump malfunction
- Wiring issues in the fuel pressure regulator circuit
- ECU (Engine Control Unit) software needs updating
Common Misdiagnosis
OBD2 Code: P0091
Description: Fuel Pressure Regulator Control Circuit Low
Common Misdiagnosis: Replacing the fuel pressure regulator without checking for wiring issues or a faulty powertrain control module (PCM).
Common Diagnostic Steps
OBD2 Code: P0091
Description: Fuel Pressure Regulator Control Circuit Low
- Check the fuel pressure regulator for proper operation and ensure it is not stuck or clogged.
- Inspect the wiring and connectors related to the fuel pressure regulator circuit for any signs of damage, corrosion, or disconnection.
- Test the voltage at the fuel pressure regulator connector using a multimeter to verify if it matches manufacturer specifications.
- Examine the powertrain control module (PCM) for any software updates or known issues that could affect fuel pressure regulation.
- Perform a continuity test on the wires between the PCM and the fuel pressure regulator to identify any breaks or shorts in the circuit.
- If applicable, check for vacuum leaks that might impact fuel pressure regulation.
- Replace faulty components as necessary after completing diagnostic tests.