Conditions for Setting the DTC: P0090

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

The fuel pressure regulator voltage is between 2.7-4.5 volts with the fuel pressure regulator commanded OFF.
The above condition is present for greater than 1 second or for a cumulative of 10 seconds.