P0090 - Fuel Pressure Regulator '1' Control Circuit
Fuel Pressure Regulators are used to control and regulate the fuel system pressure to ensure a steady and sufficient supply of fuel depending on the current engine load. The ECM will normally operate some form of electrical solenoid / motor to regulate the fuel pressure based on feedback provided by the fuel pressure sensor.
Fault Code Explained
This fault code is usually stored when an undefined fault with the Fuel Pressure Regulator Control Circuit has occurred. This could be due to a value that is outside of it’s normal operating parameters or is incorrect for the current engine operating conditions
Due to the variety of systems and methods used for Fuel Pressure Control it is recommended to follow the manufacturers test plan for this fault code.
The following are some of the general tests that should be carried out
- Check for Open / Short circuit on Fuel Pressure Regulator Wiring
- Poor Connection / High Resistance in wiring
- Test operation of Fuel Pressure Regulator Solenoid / Motor