The code indicates the fuel pressure is too high, which I believe you already know. Do me a favor. Here are a few diagnostics. Go through them and let me know what you find. If something fails during the test, I can direct you from that point.
Remove the G18 High Pressure fuel pump
Verify the lobes on the camshaft do not have unusual wear or are worn.
If the loves have unusual wear or are worn, replace the camshaft.
If the lobes are ok:
Test or replace the G18 High Pressure fuel pump
Ignition off, disconnect the harness connector at the G18 High Pressure fuel pump
Note: The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis.
Test for 9-11 Ohms at 77Â F between the high control circuit, terminal 2, and the low control circuit, terminal 1.
If not between 9-11 ohms, replace the high pressure fuel pump.
If between 9-11 ohms:
Test for infinite resistance between each terminal and the G18 High pressure fuel pump housing.
If less than infinite resistance, replace the high pressure fuel pump.
If infinite resistance
Perform the diagnostic repair verification after completing the diagnostic procedure
Fuel injection fuel rail pressure sensor replacement.
Fuel Pump Replacement
Intake camshaft and valve lifter replacement
Perform the fuel rail pressure relief valve reset procedure if supported on the scan tool.
Let me know what you find or if you have questions.
Take care and God Bless,
Tuesday, February 9th, 2021 AT 5:59 PM