P0091 - FUEL PRESSURE REGULATOR 1 CONTROL CIRCUIT LOW
POST UPDATED IN October, 2021
Description of DTC code P0091 Generic
DTC codeP0091 OBD2 means that the PCM has found a low-voltage signal from the control circuit of the fuel pressure regulator 1.
The regulator is usually controlled by the PCM. The regulator has a servomotor that places the regulating valve in the correct position so that the expected fuel pressure level is obtained according to the circumstance.
If the actual voltage of the regulator circuit is lower than the expected level, which is calculated by the PCM, this code is stored and the Check Engine light is illuminated.