Motronic ECU don't speak to me

[hub]

Hi,

My S2 3B doesn't start since one month. Since my baterry was low (I have forgotten to turn off the stereo...), I have recharged it but impossible to start the engine.

- the fuel pump turns
- I heard also the water pump for about 5sec
- all the lights on the ODB are OK

But no sparks .... So I have tryied to communicate with the ECU motronic and there is an error communication...

So I have looked on the workshop manual and they said to : "consult CFD to check earth connection" what does it means?? and where to check (ok for the inlet manifold for the pump)

Some ideas... I hope the ECU is not dead

[Le S2 Audi]

Have you tried to reset the ECU??

Pull out the fuses...

May help?

[quattro20v]

Any immobilasator/alarm installed?

[hub]

No alarm...

I have put off the fuses to check if they are ok... It is enough to reset or should I make an ignition on??

ps: There is no mapping on the ECU, it is full stock

[Rocco]

check the distributor complete or the single coil

sometimes the hall sender it is dead

[hub]

Is it possible that someone here send me a picture of the hall sender location on thé engine because Im not really sure

[hub]

But I don't understand why the ECU doesnt communicate even if the sender is dead.

[Foeglass]

does your equipment read / get contact with the other ecu's? airbag/ecu/climatronic ect?


And i saw somewhere it's possible to get the codes out with a led light / blinker codes?. correct me if i'm wrong

[hub]

Yes it is possible to read by plugging a light near the driver sit... (I don't have try actually)

I don't have airbag on my car (don't exist on 3b I think)
About the climatronic it is different from the motronic itself

[Knight Rider S4]

on a 3B you will only beable to get codes from engine controler as others not a function on 3B model

Things to check

Fuse 17
Main fuse for ECU as if it is dead you will get nothing

From the start of your problem as in battery losing charge I would look at the simple things first

Hall sender is built into distributor... 3 prong plug

[hub]

hi,
Where is the fuse 17 plz? main fuse box?? here in red?

[hub]

[M_GORDON]

Some Fuses are behind a "cap"