P0191

What does P0191 mean?

P-code P0191 means "Fuel Rail Pressure Sensor Circuit Malfunction". It is a generic OBD-II diagnostic trouble code (DTC) in the fuel system. The pressure reading from the fuel rail pressure sensor circuit malfunction is outside the expected operating range. This warning should be addressed within the next few days to avoid further damage. This code applies to OBD-II compliant electric and hybrid vehicles.

Possible Causes

• Faulty pressure sensor or damaged sensor connector
• Fluid leak causing lower-than-expected pressure readings
• Blocked pressure port or contaminated sensing element
• Pump or actuator failure affecting system pressure

Recommended Actions

1. 1 Avoid aggressive driving and schedule a diagnostic appointment within the next 1–3 days
2. 2 Scan for all DTCs with an OBD-II scanner — note any related codes stored alongside P0191
3. 3 Inspect the fuel system component and its wiring for visible damage
4. 4 Check for water intrusion in connector areas and clean contacts if corroded
5. 5 Clear the DTC, road-test the vehicle, and re-scan to confirm whether the fault returns
6. 6 If the fault persists after inspection and clearing, consult an EV-certified technician for component replacement

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