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[andyg plym]

no problem mate

i am happy for any input, makes me look at it from a different perspective

[stocious]

Interesting question.

Anyway, there is only one thing that can cause this and that's the ECU resetting.
If it's always rev based, it's most likely either a fault in software, or a problem with the engine speed sensor or crank position sensor.
Can also be damaged ECU or power supply to ECU going out.

Nothing else.

Might be a stupid question, if the g28 and the G4 sensor were swaped, as in top one in the bottom and vice versa what way would the car behave ?

[prj]

No start.

[stocious]

No start.

Thanks !

[UrS4boy]

Might be a stupid question, if the g28 and the G4 sensor were swaped, as in top one in the bottom and vice versa what way would the car behave ?

The sensors are pretty much the same at the engine end so it is potentially possible to sway them by mistake (but you'd have to try real hard). One solution would be to also swap the connectors at the fire wall. But that is dumb. Just get the sensors in the correct position to start with is the better solution:

G4 (Item 14): 034 905 381 igntion timing sender (black)
G28 (Item 15): 034 905 381A engine speed sensor (grey)

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

[newsh]

Andy, read your posts quoted below. Is that code 65525? or 65535? I think you're confusing yourself there

http://wiki.ross-tech.com/wiki/index.php/65535

MAJOR UPDATE:

Contacted merlins4 (aka Tristan) and to cut a long story short took my ecu to try on his car (cheers pal hope you like the wine and beer!).Both RS setup.We connected it and it drove FANTASTIC!!

Pulled to 2 bar really hard. We got back and put a code reader on it

00002
65282
65535
00255

are the codes that were stored, am I right in thinking that once ecu's are disconnected the codes get erased?
Need to check all the sensors as already mentioned on here asap, anyone know what these codes "could" mean?

65535 - one of the chips is probably bad.

But if it works on the other car you have issues with your engine speed sensor or crankshaft position sensor or flywheel pin.

65525 when googled comes back to an airbag problem.Today I test fitted an airbag steering wheel on my non airbag car,it did have the 2 pin plug which i connected up.
But, this was obviously before I disconnected my ecu to try on the other car and now it shows up...

I thought codes were deleted once ecu removed?

[Monkeymagic]

65535 is an internal memory fault meaning ecu shot.
it is a common fault with air bag controllers. but obviously can affect any module

[andyg plym]

65535 is an internal memory fault meaning ecu shot.
it is a common fault with air bag controllers. but obviously can affect any module

Right so this particular code is airbag module related not actual ecu related ? Just so in clear

[Monkeymagic]

un plugging an ecu won't make it forget the stored codes.
why not try your mates ecu in your car. ? see if problem persists. if not the answer is there. if so then you've ruled something out. you need to get your obd working so you can watch various bits etc.

[driftin jo]

un plugging an ecu won't make it forget the stored codes.
.

YES IT WILL

[andyg plym]

un plugging an ecu won't make it forget the stored codes.
why not try your mates ecu in your car. ? see if problem persists. if not the answer is there. if so then you've ruled something out. you need to get your obd working so you can watch various bits etc.

If only !! My mates cars ecu is a switchable ecu so he had wires connected to it etc etc and as he was doing me a favour I didn't want to push it

[andyg plym]

Just got back from my ecu guy who said after doing his tests there was nothing wrong with the ecu

Time to start digging then, need to figure out why obd port not working

[Rusty]

Check that you have voltage on the black plug.

Something I noticed after fitting my alarm is that the immobiliser stops the VAG Com lead from working... This is obviously down to my choice of wire to disable the car. With that in mind, make sure that the fuse box wiring is all correct

[andyg plym]

Rusty the black plug is dead !

Saying that the factory con log immobiliser has been disconnected by the last owner

[Rusty]

That's your issue then, you need 12V at that plug to power the code reader.

I don't think that plug is the one that's been immobilised, as I get a light on the lead. I will need to look but mine's to do with one of the immobilisation points I've chosen. They're effective for sure and a lot better than the method chosen for the original installation back in the stone ages, which allowed the fuel pump to run flat out with no cut-off!!!