The P0091 trouble code indicates a low voltage issue within the fuel pressure regulator control circuit. This code typically points to issues with the control circuit responsible for managing the fuel pressure regulator, potentially leading to improper fuel pressure levels and affecting the engine’s performance.
Fuel Pressure Regulator Control Circuit Low
Code symptoms P0091.
1. Fluctuating engine performance.
2. Decreased fuel efficiency.
3. Illuminated “Check Engine” or “Service Engine Soon” light on the dashboard.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0091.
1. Faulty fuel pressure regulator.
2. Low voltage within the control circuit.
3. Problems with the Engine Control Module (ECM).
Code Solutions P0091.
1. Inspect and, if necessary, replace the fuel pressure regulator.
2. Check and repair any low voltage issues in the control circuit.
3. If ECM issues are suspected, consult a qualified technician for diagnosis and potential reprogramming or replacement.