Wont start sold a dud any advice appreciated !

Evening all,

Can anyone help,

got a 2010 a3 cab couple weeks ago, and its broken down. towed it to one garage who gave up and now its back outside my house.

it all started with flashing glow plug light, then engine management light came on, followed by a host of others after disconnecting the battery, at this point the car would still drive and all but the EML and glow plug light was on. it drove for another couple miles then just cut out. though I do remember the stop start flashing before it cut out for good.

Error code, fuel pump A open circuit, fitted new fuel pump wont start or activate the pump, seem to be getting 12 v at the fuse in the side panel if i got the correct one. swapped out the little relay by the knee section, though i wasnt sure which exact one it was for the fuel start relay so i just swapped them all out but it did nothing ( it was the little type, not like the old big square ones)

when i turn the key it cranks over, but wont fire up. even when turning the key two notches you cant hear the fuel pump trying. also I couldn't seems to get any voltage at the pump wiring as i thought it may be a dead new pump and the old ones gone too but assume this is not the case. ( assume its the two big wires)

garage put fuel in the inlet and it started for a second.

it seem to fire up a host of warning lights, at one point, then just glow plug one which kept flashing

is there a fuel pump cut off from crashing that i can try resetting?


further to this i tried to access the immobiliser settings using the icarsoft CRmax which said test failed like it couldn't reach the immobiliser.

If its an open circuit can anyone help with how to prove continuity for the wires as i dont know which one leads where! despite downloading a manual it makes bugger all sense tbh.


throw every option at me I'll try it ! thanks in advance

I did find this but have no idea if its for the a3 it seems to show a line diagram with this as help

what do you guys think? if its a goer, can any one explain in dumb terms for me sorry

So- maybe a first step might be to check the status of SC2 - does J17 actually "click" with ignition ON? If not, grab a multi meter and check voltage on T30 and T86 pins on J17 (battery rail volts). If OK, does Pin #2 go to earth potential with ignition ON? If not, check integrity of wire/connectors from J17, pin #2 to pin #80 on ECM (i.e. the 121 x pin connector)

https://forums.ross-tech.com/index.php?threads/32663/

Still looking for help,
Update

• I put power to the old pump straight from the battery and it works,
• i then tested the continuity from the earth at the pump to ground that seemed ok,
• found the relay under steering wheel, where the live from the fuel pump goes, that wire is ok.

so I now know pump is ok, and the wires going to the pump are ok (well the main power and earths.

• there is 12v getting to the relay, and i know the cable to the pump is ok,

So somthing is not sending a signal to the relay to engage or the relay is buggered, but i swapped it for others in the panel and nothing

• I then i short circuit the relay and the pump starts. but the car didn't start though battery was fading, so I'm now wondering if its the imobaliser again. though I'll try that again when the battery is charged back up.

2 new questions- does the imobaliser stop anything else other than starting the fuel pump?? and where do the 2 small wires go from the relay?

hope someone pick this up to help cheers

throw up your scan report let us see what is going on.

If the factory fitted immobiliser is activated, the engine will start and then immediately cut out so if it is just cranking over, it isn’t the immobiliser.