ECU 2 fault
 

The Ross-Tech VCDS shows a fault code as follows; 16672 - Please Check DTC Memory of ECU Number 2 - P1923 00 [00100111]
Does this mean a new ECU?

No. P1923 is more like a comment to inform you that there is an error code in ECU2. The V10 and W12 engines have dual ECUs.

You need to go into ECU2 and check to see what the error code is, resolve it and clear it, before you can clear the P1923 in ECU1.

Very informative, thanks. Where do you find this stuff?

Found out about it when I had the D3 S8.

I don't see anything obvious which says ECU2 and there's only that single fault code relating to it, which I can clear, but the fault comes right back.
There is no visible effect on the car that i can pick up as a result of this fault.

Try connecting manually to ECU2, I think it's address 11. ECU1 is 01.

If I go to address 11 I see the fault code in there, and can clear it, but it returns. I can't see anything else in there. Am I missing something?

What is the specific fault code that's showing in ECU 2? Are you able to include the full part of Address 11, as opposed to just the fault code line itself?

Sorry I've only got around to this. Here's channel 11 log;

Address 11: Engine II (J624) Labels:. 07P-906-023-V1.clb
Part No SW: 07P 906 027 A HW: 07P 907 309
Component: W12 6.3 EU6 H22 8556
Revision: 41H22000 CVN: 077AE0AA
Coding: 002A0012256601000800
Shop #: WSC 23485 002 1048576
ASAM Dataset: EV_ECM63FSI21107P906027A 001011
ROD: EV_ECM63FSI07P906027.rod
VCID: 303ECF06AAA4CF7A3F1-8064

1 Fault Found:
24749 - Exhaust Pressure Control Valve 2
P04A2 00 [00100111] - Short to Plus
Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 120237 km
Date: 2025.03.06
Time: 16:38:05

Engine speed: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 90 C
Intake air temperature: 45 C
Ambient air pressure: 980 mbar
Voltage terminal 30: 12.203 V
Unlearning counter according OBD: 40
Engine torque: 0.0 Nm
Fuel level: 28.00 l
Intake camshaft B1 active operating state: 0

This is the error mentioned in your other thread:

https://forum.a8parts.co.uk/showthread.php?t=17372

Have you tried my suggestion in that thread to see what happens?