BMW 520i E39 I can't start engine.

[lucasmaster]

Hi.
I have BMW E39 2.0 1996 with Siemens MS41.0 Ecu.
I can't find a solution to start engine.
I can't connect to the ECU to read fault codes.
I check all grounds to ECU and power it seems to be OK.
But i find that ECU dosn't send a ground to Main Relay, after i gave ground there i hear that everythings starts to power up, but fuel pump dosen't and the engine dosen't start.
Maybe someone of You guys have a similiar problem with this car.
I think that will be ECU. Any other ideas?

Rgds & Thanks for any help
Lukasz

[oep]

You should scan your car for DTC's.
Also you can try checking fuel lines pipes filter etc. is there fuel coming to engine?

[lucasmaster]

You should scan your car for DTC's.
Also you can try checking fuel lines pipes filter etc. is there fuel coming to engine?

Like i said, I can't connect to the ECU, I try with X431 and many other tools with no luck.

[oep]

You try connecting kline directly to ecu from obd2?
Don't get it.. was car ok driving then stooped or you drove it out from garage after x years?

[decno1]

If you cannot communicate with ECU you only the following possibilties:
1- The DLC wire is short to B+ or ground, you can make sure by:- if you can communicate with other Ecus, means DLS ok
2- The bus of ECUs communications is not OK
3- Ecu not powered.
4- The Ecu is faulty

I think the most popular option is No.4

Try to replace the ECU, then make ECU/EWS sync, the engine must run.

[cars]

Should understand if you can not communicate with the ECU for fault diag tool or because the ECU is isolated or off
You have checked the engine speed sensor oscilloscope?
I tried the second key starter to exclude immo master key.

[brownbajan]

does the engine turn over

[djscotch]

I think ECU is dead...

[lucasmaster]

Thanks for help dead ECU

[daniel sg]

Thanks for help dead ECU

Hi.
Cheks nec inside ECU.