Management light NISSAN Juke (F15) (06.2010 - 12.2019)

If your Nissan Juke (F15) has a constant Check Engine light with a P0090 code, and the car runs fine, then the problem is most likely in the electrical control circuit of the fuel pressure regulator.

The P0090 code indicates "Fuel Pressure Regulator 1 Control Circuit - Open/Short".
What could be the cause (other than the pump that has already been replaced):

- Wiring or connectors: The most likely cause. Damage or oxidation of the wiring / connector going to the fuel pressure regulator (on the injection pump or rail).

- Fuel pressure regulator (FPRV): The electromagnetic regulator itself may be faulty (internal open/short).

- ECU malfunction (ECM): Less often, but a malfunction in the engine control unit is possible.
What to do:

1. Reset the error code using an OBD-II scanner. Drive the car.

2. If the error returns:

- Carefully check the wiring and connectors to the fuel pressure regulator.

- If the wiring is OK, then the problem is most likely in the fuel pressure regulator itself.

The fact that the car runs normally indicates a "floating" problem or ECU compensation, but this requires attention.