Need some help with fuel pressure sensor error P0190

[Braden57]

If anyone's seen any of my recent posts, you'll know I've recently been doing a lot of the "supercharger off" replacements and cleaning (pcv, thermo, wp, pipes, hoses, hx, carbon cleaning, etc - also new belts & tensioners). Just got it all put back together yesterday, filled with coolant, no leaking. Engine sounds smooth, steady idle. BUT...I am getting one troublesome code - P0190 (Fuel Rail Pressure Sensor Circuit Malfunction). The car is starting slightly slower than normal, but again once it starts, it's nice and steady.
I understand that code is not necessarily saying the sensor itself is faulty, but that the wiring is either not connected or only getting an intermittent connection. Since I'm getting no other codes, I'm guessing the problem is right there at the sensor (I find it unlikely I damaged wiring somewhere else and somehow coincidentally only damaged wiring to something I actually fooled with). So either the sensor is bad (I did replace it with a new one), or the electrical connection there is damaged somehow, or I was just dumb enough to not plug in the harness all the way .

So questions...
Has anyone else had this issue and code after removing and replacing that sensor?
Could it be anything else? I think I've read other people having this code but replacing fuel filter or hpfp ended up fixing it. Again, I just find it unlikely to be other stuff since I was messing with the sensor, but just checking.

Most important question - when I remove the supercharger to check the wiring connection, is there any issue if I turn the car power on to check codes while I am in there? I know I'll get a bunch of other codes since a lot of other wiring will be unplugged, but no harm in that right? I'm thinking I'll just unplug the secondary water pump to make sure no coolant will be pushed around. I want to make sure I address the problem without having to do supercharger on/off multiple times.

TIA for the help.

[SwankPeRFection]

There is a pressure sensor on the fuel rail on the driver side that you either forgot to plug in or something else is happening with the wiring. You’ll see it when you pull the charger off and lift the heat pad up. Could be that connection. Yes, it should be fine with the secondary pump disconnected so it doesn’t push coolant around. Just be aware that you’ll see other errors and you may also not be able to get that code to clear and come back or not come back without starting the engine, so I can’t answer that part. I have a feeling you just missed plugging in that sensor, in which case, that’s probably it so plug it in and put it all back together and clear codes and it should be fine, no need to mess with testing with it all taken apart since that’s clearly the obvious culprit.

[LowKeyLoki]

Before you start digging to remove the SC to locate the problem…have you logged/monitored parameters through VCDS like fuel rail pressure? Check things like injector duty cycles and the low pressure pump. Watching those and rail pressure read out (if it is reading at all) should narrow down the problem whether it’s the sensor itself or HPFP/lpfp.
As for checking the wiring you don’t need to turn on the car, all you need is a multimeter and back probe the connectors to the ECU pins and check resistance/continuity, you will of course need the factory wiring diagram to locate the pins.

[SwankPeRFection]

It won’t give him fuel rail pressure with that sensor circuit malfunction.