P0090 2007 LBZ. Won't clear even when engine not running.

[Fmt2bx]

Hi, new to the forum.

Spent a lot of time researching before posting. I have a P0090 (Fuel Pressure Regulator Control Circuit). I am using a Launch scan tool.
Upon getting DTC, the tool took me to the "live data" and everything there seems perfectly ok when I compare "desired" and "Actual" values.
I couldn't not delete the DTC with engine running or off. As the DTC specifies "Circuit issues", I unplugged and replug the FPR, move the harness around and was able to clear the code after that.
So, looks like it could be a bad wire buried in the harness somewhere.

Would anyone know or have access to a proper wiring harness schematic and could tell me what wires are used by the ECM to monitor a P0090 code?

Thank you

 

[Ron Nielson]

See the attachment and do the testing outlined as well as you can. What year and engine family do you have?

 

[Fmt2bx]

See the attachment and do the testing outlined as well as you can. What year and engine family do you have?

Thank you Ron, I have a 2007 Duramax 6.6L LBZ.

 

[Ron Nielson]

https://www.gmupfitter.com/wp-content/uploads/2021/05/2007_LD_ElectricalPickupsChassisCabs.pdf

 

[Fmt2bx]

https://www.gmupfitter.com/wp-content/uploads/2021/05/2007_LD_ElectricalPickupsChassisCabs.pdf

Thanks!!!!