HELP from ECU guru's is needed

[kwlw]

Hi,

I had some nightmare with ECU wiring, and after some playing with ecu power terminal inputs, I have two dead ECU's as a result.

ECU's are M2.3.2 one from S6 AAN, other from S2 ABY. In both CPU's start, however ECU is not reacting to any I/O.

So there are my two questions:
1. Do someone knows what chip hides under BOSCH B30015, as far I understand this chip stands for ADC/DAC with serial I/O, and probably is made by AD or TI.

2. What possibly could die, when motronic ecu gets +12v for example only from one of three required inputs.

PLEASE HELP! its very hard to see car standind dead

Sau
P.S. I can't afford to buy another ECU (I've already three of them), however I have almost unlimited time resources to invest into this case :/
P.P.S. I'm afraid to connect third ECU to the wiring loom, because I don't know what was the reason for them to blow

[Doug_RS2]

Has your car wiring been butchered? Or are you damaging these ECUs on the bench, trying to power them up?

[kwlw]

Has your car wiring been butchered? Or are you damaging these ECUs on the bench, trying to power them up?

I have put AAN engine into typ85 coupe quattro. Everything was ok, the car was running fine on temporary "spaghetti mess" until I've decided to make new "stable" wiring, using fuel pump relay, etc. Then the problems started.

I've verified wiring several times, it is correct according SJM's page and S2.net diagrams. It seems that at least I/O chip in both motronics died .

Sau

[S2central.net]

How do you *know* this I/O chip is dead ?

I've repaired a few 'dead' ECUs in my time that suffered failures of protection diodes... which of course is due to a wiring fault of some kind.

I also think you need all supply and ground rails properly connected for tests of any kind due to the various analog and digital ground rails within the ECU. They must ALL be connected - are you sure that all 0V points on the ECU are connected to chassis earth ?


Paul

[kwlw]

How do you *know* this I/O chip is dead ?

I've repaired a few 'dead' ECUs in my time that suffered failures of protection diodes... which of course is due to a wiring fault of some kind.

I/O chip stands between CPU, and I/O lines . So it was the suspect No.1

Thank's to the neat ideas. Yesterday we connected better osciloscope to the ecu's, and it seems, that I/O chip is OK . I mean it reacts to the inputs, and gives output.

I will try to check the diodes, howether this may be not my case, because I havent mixed + with ground. But thanks for support anyway.

IMHO cpu is now looping in some wait for interrupt or infiinite interrupt loop, which may be caused by burned input. However I don't have enough knowledge and ECU schematics to verify that.

I also think you need all supply and ground rails properly connected for tests of any kind due to the various analog and digital ground rails within the ECU. They must ALL be connected - are you sure that all 0V points on the ECU are connected to chassis earth ?
Paul

This was the first thing I've done . And for my frustration, all of them were connected, and properly .

Sau

[kwlw]

problem solved

Friend of mine managed to repair two ECU's . It was BOSH 30015 I/O controller (like I've suspected) which was causing problems. For some reasons this chip died on both ecu. I managed to get BMW ecu for parting, and now my ecu's are ALIVE!!

Today I've driven 3.4 km's in my test road which is 30-40m total length . ice and summer tires combination of course

Thank's everyone for ideas.

Sau