engine turns over but doesnt start P0321 engine speed sensor input circuit incorrect signal.

[julianb]

Ive a Passat B6 2007 2.0D (196k MILES) and the engine has just died: Vag says "p0321 engine speed sensor input circuit incorrect signal"
haynes says "the engine speed sensor is mounted on the frontleft hand side of the cylinder block, adjacent to the mating surface of the block and transmission housing."
Ive been lead astray by haynes recently (you dont need to remove the rear calipers to replace the rear disks.) Can anyone help with a more exact location perhaps with a picture?
VAG ALSO SAYS "DTC: P1266,Valve for pumpinjection, cylinder 3; imlausibles signal" Frankly that looks expensive so I thought I would look at the engine speed sensor first.
any guidance warmly received.

[martin1810]

Speed sensor error will not stop car starting. Engine has camshaft and crankshaft sensors. Either will start the engine. A failed injector will prevent engine start. That is your main fault.

[DMitch16]

There's a wiring fault somewhere in the injector loom (no 3 cylinder) as the engine speed sensor is a common red herring thrown up by loom faults. Or as Martin1810 states the injector itself is at fault and unfortunately will be expensive.

[julianb]

Thanks Guys, I cleared the error codes and they have not reoccurred. It feels like a fuel starvation problem. Currently workin on that: the Fuel filter barrel is not full and not filling on turnover although theres a definite suction. My guess is fuel tank filter, I think there is a fuel tank lift pump but I would have thought a malfunction would have created a fault code.

[RichardSEL]

TDi fuel pump filter block doesn't create its own error code -- only red herrings if that
Tapping its side may dislodge sludge build up from the sides of the fuel filter, but only to have it return
Complete pump has to be replaced as internal filter a non-changeable item by itself

[julianb]

So it did turn out to be the electric fuel pump in the fuel tank. An easy fix for £100. The engine sings as sweetly as before. I guess the moral of the story is: use the error codes for guidance but use your brain and experience too.
Thanks for all your help.

[DMitch16]

Great result - on the error code subject I have found that not all error codes are genuine and relate to the problem encountered. It's as if in rarer cases the ECU when it is not able to make sense of the signals received throws a guess at another component on the car. The crank speed sensor often seems to be one of the default red herrings depending on the nature of the actual problem.

[martin1810]

The error codes from the ECU are set by very precise logic (no guesswork). It is up to humans to interpret the codes. Sometimes we can, sometimes we can't.