I had a message from a user on another forum that asked if I could help him out as he lived local with his 2005 Audi Q7 3.0 TDI.
It appear that his wife had filled up with petrol it must have been a lapse in concentration. She realised her mistake and didn't try to start the motor. It was towed back to their home and he had a garage come around and drained the tank. As I understand they sucked the fuel from the tank via the fuel filter feed pipes into a tank on their vehicle. They connected a pipe from clean diesel on their vehicle back to the fuel filter. They started the motor up and he said it ran ok for a few minutes. They disconnected their pipes and connected the vehicle pipes after adding clean diesel it started for a few seconds then stopped they said it could be a faulty fuel pump or wiring and left him to it.
He wanted the fuel pump running to bleed the system. I did an Autoscan first just to check there is nothing else causing it not to run. There were 15 systems with faults the only one for the engine was:
VAG Error Code: 17471
EOBD II Error Code: P1063
Fault Location:
Fuel Pressure - Control Limit not Reached
Possible Cause:
Air in fuel system.
Fuel system leak.
Fuel lift pump.
Fuel bypass valve.
Fuel pressure control valve.
High pressure fuel pump.
I went into
Engine can clicked
OutPut Test - 03. Now there was no combobox to select Fuel Pump Relay so I had to cycle through the other components first. It showed the Fuel Pump Relay being switched On/Off but we couldn't hear the pump running. I checked the wiring diagram to find any fuses or relay. The relay is in the engine fuse/relay box after removing the screws we found it.
I removed the main fuel feed pipe to the filter and put it in a container. I went back to VCDS but it had cycled through to the next test. I came back out and tried it again and it came up with an error with something like system not enabled. I shut down VCDS and tried it again but it showed the same message. I switched the ignition off an tried it again and it operated the relay you could feel it clicking. So his problem is either its a coincidence that the fuel pump has stopped or he has a wiring fault or its something to do with P1063 error. I said he needs to check if the pump has a good power supply and earth.
I've google it this error code and one user said he cured his by replacing the fuel filter but that would fix why the fuel pump doesn't run.
Oh there is a new update out
VCDS 11.11.4