HC4 - Check Pressure Regulator Diaphragm

- Key Off.

- Fuel pressure tester installed.

- Start and run engine for 10 seconds.

- Key Off, wait 10 seconds.

- Start and run engine for 10 seconds.

- Key Off, remove vacuum hose from fuel pressure regulator.

- Inspect for fuel in the vacuum hose or regulator port.

- Is vacuum hose and regulator port free of fuel?

YES -- GO to HC11. HC11 - Check Fuel Injector Flow and Leakage

NO -- REPLACE fuel pressure regulator. Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes