Where is the vacuum advance located on a 2003vw Passat

It is on the end of the fuel rail, and easy to replace just by removing the clips. There is also a vacuum hose. But test rail fuel pressure first.

Right at the far end of the main fuel rail on top of the engine.
It also have a vacuum line to it.

gear shifter as transmission inside it. well best replace transmission or you'll need a pulley and few sockets. as the shift. the shift you pull the knob or act as if you are prying it out it stay out. once out far enough push down on the bottom sparkling part of the stick. once down pull knob. then fallow the screw on side for removal.

it should be under the steering wheel but sometimes its in the dash board/glove box

on firewall driver side

ecp, if i remember correctly is your engine computer light. sounds like a dealership may be needed.

P0411 is an indication of a MAF sensor (mass air flow). A common cause is the vacuum lines conneted to the MAF. A leak or worn vacuum line will throw a P0411. Check the lines going to the MAF (near the air filter). If the lines are good, then replacing the MAF should solve your problem. Best of luck.
Greg

Go to schucks/kragen/chiefs and have the codes read...then it will go away if you fix what it is faulting.

the passat has an alarm unit in the boot with battery backup.
This is common to failing and is in the left hand side of the boot

Not sure where a cheap Rubber elbow is located on a passat. But do take off the coil covers. They are located under the engine cover. They are the 4 square caps. They come off with a allen wrench i believe 5mm. Then pull them off. Due this 1 at a time. Once off look down the hole with a flashlight.
And look at the rubber surrounding the coil. Their should be no moisture. If their is moisture try blowing it out with compressed air.