ECU A's & B's

[HPmuirt]

Hey guys,

I just plugged in a new ECU. The car starts and dies instantly, every time, no matter how much I rev it. When I turn on the ignition, there is a loud click from the ECU, then when the engine starts, there is another relay click and the rev counter dies instantly (the needle just plummets).

It was reported as running when sold and I assume that the ECU is OK. The number on the new ECU says 895 907 551 B whereas my original is 895 907 551 A.

Does this mean that the new 'B' ECU is a later version with the immobiliser function? If so, is it possible to bypass the immobiliser function or what ever is causing this?

Before you ask, I have PM'd the expert, but Paul has not been online since the 5th

Cheers n

Si

[BRY]

PM'd

[terrybullwon]

think this is due to the immo, maybe try a none immo

[terrybullwon]

BTW i have a non immo to try if you would like

[kwlw]

I just plugged in a new ECU. The car starts and dies instantly, every time, no matter how much I rev it.

Do you have another ECU, which works perfectly in your car? I mean what happened to your old one?

Sau

[audiman]

I think that that is a later immo ECU.
I havent tried this myself, but from the wiring diagram, it appears that you may well be able to earth one of the terminals on the ECU. Im not 100% sure on that as i havent tried it. I would like to see what input the immo control unit sends to the ecu.

[HPmuirt]

Thanks for the replies guys, it def sounds like the immo is the issue

I think that that is a later immo ECU.
I havent tried this myself, but from the wiring diagram, it appears that you may well be able to earth one of the terminals on the ECU. Im not 100% sure on that as i havent tried it. I would like to see what input the immo control unit sends to the ecu.

Now that is VERY interesting. I assue that this just fools the ECU into thinking the immo signal is present, rather than causing any permanent damage? That def sounds like the answer...Cheers Tom....just gotta track down the wiring diagram for the ECU now

Cheers n

Si

[HPmuirt]

Do you have another ECU, which works perfectly in your car? I mean what happened to your old one?

Sau

Yes, the original is back in - well flapping around the passenger foot well, but plugged in and working.

BTW i have a non immo to try if you would like

Thanks for the offer but I still have the original one thanks. The new one is for playing with (I like to keep the original parts so I can return the car to stock if need be)

Cheers n

Si

[audiman]

like i said, i havent tried this so i wont be held responsible if it does cause damage. but there is only one wire that goes to the ECU from immo control unit.

wiring diagram is on s2central.net

[S2central.net]

This absolutely is the IMMO... The 'B' ECU needs to chat with the factory immo to let the engine continue running. A 'B' ECU can readily be converted to run with IMMO functions disabled. I'll do it for nearly nothing plus postage if you like.

Paul

[HPmuirt]

This absolutely is the IMMO... The 'B' ECU needs to chat with the factory immo to let the engine continue running. A 'B' ECU can readily be converted to run with IMMO functions disabled. I'll do it for nearly nothing plus postage if you like.

Paul

Ah hah... Hi Paul , yes please Paul , thanks Paul

PM on its way

Cheers n

Si

[audiman]

@ Paul, any idea on what signal the ECU recieves to allow it to start? Is it earthed or is it a pulse signal or something similar?

[kwlw]

@ Paul, any idea on what signal the ECU recieves to allow it to start? Is it earthed or is it a pulse signal or something similar?

S6 AAN ECU talks using pulse signal. ABY may be similar.

If you replace immo, you need ecu to "learn" new box.

Sau

[Jon441cc]

Si i have a non immo aby ecu you can borrow if you like?

[HPmuirt]

Si i have a non immo aby ecu you can borrow if you like?

Hey Jon,

Thanks for the offer matey but no need, as this is a second unit to play with :mischeif: The eventual plan is to get the car MRC'd with all the RS2 goodies bolted on, but I always keep the original parts removed (I even have the orig brakes )

The original non immo (A) unit is back in the car and running fine and the immo unit (B) is in the post to Paul N as we speak to have the immo function removed.

Thanks again

Cheers n

Si