Non starting AAN

[slacky]

Ok being trying to get to the the bottom of this without success so far ...

Wouldn't start one day when typically being used by the mrs with her mother in the car
Borrowing 20vcqdriver's plugins to diagnose the problem , initial response was speed sensor (G28) & crank sensor (G4)
Replaced both
Stuck on vcds again, came up with what I was suspecting camshaft hall sensor (G40)
Replaced this , still no good .
We believe there's fuel coming through (checked at fuel filter junction) so I'm assuming the fuel pump is operating??

Any thoughts or assistance would be greatly received as I'm missing playing in the 6

Many thanks Chris

[shaun5]

How much research have you done? When i couldn't start the S4 i had (bought as a non runner) i found there were lots of things to check but can't remember now.

Pretty sure there are fuses next to the ECU (Passengers footwell) to check. I made up a LED test lead for the cam sensor to check it was receiving a signal. I ended up giving it some sniffing salts to make it start and then for some reason it decided to run!!!!

[spink]

Take the cover off the fuel pump Relay and close the contacts with your fingers,the pump should be audible when engine off,now try start it

Those codes could have been old codes from being disconnected at some point I suppose ?

[slacky]

How much research have you done? When i couldn't start the S4 i had (bought as a non runner) i found there were lots of things to check but can't remember now.

Pretty sure there are fuses next to the ECU (Passengers footwell) to check. I made up a LED test lead for the cam sensor to check it was receiving a signal.


( )
I ended up giving it some sniffing salts to make it start and then for some reason it decided to run!!!!

Sorry my bad , I forgot to say we checked those fuses prior to replacing the above parts ....

[slacky]

Take the cover off the fuel pump Relay and close the contacts with your fingers,the pump should be audible when engine off,now try start it

Those codes could have been old codes from being disconnected at some point I suppose ?

Thanks spink I'll try that tonight

[Error404]

Here you go Chris:

http://www.s2forum.com/forum/showthread.php?t=49771

[slacky]

Here you go Chris:

http://www.s2forum.com/forum/showthread.php?t=49771

Thanks Alex ,

[UrS4boy]

Potential solutions to why your AAN (or ABY or ADU) -powered UrS (S2/R isn't starting

Here you go Chris: http://www.s2forum.com/forum/showthread.php?t=49771

Also:

http://forums.quattroworld.com/s4s6/msgs/210191.phtml

Which is Item 4 in the latest version of my Monthly reminder list:

http://www.s2forum.com/forum/showthread.php?t=63388&page=3&highlight=potential

[slacky]

Also:

http://forums.quattroworld.com/s4s6/msgs/210191.phtml

Which is Item 4 in the latest version of my Monthly reminder list:

http://www.s2forum.com/forum/showthr...ight=potential

Thank you Dave

gotta lot to look through now ,thanks to everyone for their input today much appreciated

[Taavi]

Check the timing first. It is always a must if there is G40 error.

[slacky]

Wave form checks -
G28 good sign wave
G40 perfect square wave pulse
G4 nothing
Checked supply to plug no volts on any with ignition on
Checked & pin is present on flywheel

Is this looking like an ECU fault?
No voltage from Pin 47 with ignition on .....?

[slacky]

Would anyone be willing to test my ECU if I post it to them ?

[twoqu]

Might it be worth physically swopping the crank/speed sensors over to rule out a dead sensor. I know they are relatively new so should be easily able to be swopped. If you then get the crank signal but not the speed that would confirm a dead sensor.

[slacky]

Might it be worth physically swopping the crank/speed sensors over to rule out a dead sensor. I know they are relatively new so should be easily able to be swopped. If you then get the crank signal but not the speed that would confirm a dead sensor.

good call worth a try

[twoqu]

I don't think either of these sensor have any power. They produce a signal if you see what I mean.
They appear to be earthed via pin 19 which is one of the inlet manifold earths. So I would have a look at that closely, although you would have expected both to have been effected by an earth problem!