Greg_S S2 Coupe 20+ years going strong

[Rusty]

just chase the immobiliser wires; you may have to unbolt the fuse box to get to the wires, unless the fitter has been really lazy.

I identified to places that both prevent starting. One is the fuel pump and the other was spark related. Can't remember if I wrote it down or not

[Error404]

I agree with John, sounds like immobiliser issue to me

[Greg_S]

I'll see if I can get some more this week. I had a about 15 mins this afternoon to take another look with a fresh head.

Ive been using a voltage test probe and the two "Moteur fuses" were my first port of call today. I should have taken a picture at the time too, anyhow one is permanent live when tested and the other I assume is ignition live?
One of them never gets a voltage when the immob and ignition is on or when turning engine over so I reckon this is a good place to start and will check the wiring diagrams and start to check the wiring from the immobiliser also

[PRY4SNO]

This thread needs more pics!

[Greg_S]

I've checked all of the fuses in the fuse box and also checked that the relays on the immobiliser are operating correctly. I'm sure it's a bad connection somewhere, I've just go to find which connection is the issue. It may be the wiring from immob onwards is the problem though

[newsh]

Its not just an immobiliser issue is it Greg? Strange that VCDS doesn't work, so possibly immob has cut supply to ECU, or motor fuse blown

[Mikes2]

This may help

http://s2-audi.co.uk/tech_articles/motronic/ecu.htm

[Greg_S]

Thanks Andy, I've been searching around for the ABY Ecu Pinout this evening too so I can check the supply to ecu is working before I go to g28. That link you have provided is really useful and will be taking a look at that this week. I've had to concede that I'm not going to have it fixed for the morning, but suspect a bad connection somewhere along the way. I'll start by checking ecu pins

• pin 18 12v supply
• pin 27 switched 12v supply
• pin 10 ground
• pin 12 5v to hall sender
• pin 19 ground
• pin 27 12v supply
• pin 30 ground

If that doesn't find anything I'll start checking the connectivity to G4 and g28 and diagnostics to fuse box

[andy10v]

G28-ECU-Rev counter

http://forums.quattroworld.com/s4s6/msgs/20986.phtml

G28 triggers the fuel pump relay

[Greg_S]

Does anyone know which sensor is used for rpm signal on dash?

[Greg_S]

Anyone got a vagcom I could try nearby Bedford tonight?

[Greg_S]

Should the Rev counter move when turning the engine over? Been trying to run vcds again and can't find modules. Wondering if it could be ecu or earth problem now...?

[Sonic]

Down the passenger side yes - you can see it if you remove the rear bench.

[Greg_S]

Where do cables for fuel pump run along the passenger side and into dash?

[Greg_S]

What are the fuel pump wiring connections. Green yellow should be positive supply and brown return to Earth? Two smaller for fuel level sensing. I've verified pump works with voltage tester go to work out where the circuit is broken now.