Help me diagnose this : the car, a 2018 GTS, was sitting for the last two weeks with battery and ecu disconnected. Today I tried to start the car : very rough idle, a lot of smoke, an error message about power reduction mode, and MIL on. Scanned with an obd2 scanner, P2295 error. It is a bank2 fuel pressure regulator circuit low voltage. Where I have to look??

 

Obviously I have checked the fuses, and they are all ok.

 

Clear the code and run it until all systems are properly on line. I remember something like this happening to my 997 and it ended up fixing itself after a while.

 

Here is the verbiage for Code 2295

Diagnostic information DME
(DFI) control unit
Quantity control valve driver
Diagnostic conditions
I Ignition on > 5 second(s)
Possible fault causes
J Loose contact or corrosion on connectors or lines
J Short circuit to B+/ground/between lines or open circuit in the lines
J Quantity control valve faulty (in fuel highpressure
pump)

 

Get a battery tender and store the car with everything connected. I've done this for up to 3 weeks, while traveling, with no issues on return. Some here store their cars all winter this way too.

 

If I clear the code, it appear right after the next start, and the engine is very rough and stall.

 

Do you have also the instructions on what to check with a multimeter? There is an online workshop manual for the 991?

 

Try to reconnect the ECU connections again. Maybe you didnt get it tight when you removed the ECU.