Hi

i need help with Engine ECU 8E0909557H 0001 Me7.5

Bosch: 0261207978
Soft: 1037 363630


Problem: Car Starts Up and drive good. After undefined Time Engine Stop running and ECU not aviable via VCDS / AMT and others. After Stop running Coolant-Fans running. If i cut off ignitation with Carkey and take on again the Fans off. ECU not aviable. If Car stands an Hour it Start without Problems after the Stop.

It gives not specified timed Range for Engine Stop and ECU not aviable. On Test Engine Run an Hour with Problems and cut off, other Test it Runs 5 Minutes and cut off. If Engine not Starts the ECU is not aviable on Diagnostics.

I pull ECU out of car and test on Table.

On Bench same Error with no specified Timeline.

Example ECU starts and VCDS read Measure Blocks. I choose for Test Engine Coolant Temperture, Engine RPM and Supply Voltage.

Same Issue on Table.

Error Codes on not Fitted Componets active. ( Throttle, Sensors aso. )

Sporadic on 1 Time i read out: 18048 Ecu Defective ( EEprom Error ) P1640 - 008 sporadic.

On my 15 Tests this Error only one Time.


After this i read Flash ( 29F800BB - 70 ) and E2 ( ST 95040 ) via OBD.


Checksum are Good.

I replaced the 2 Memories in Hope this is Error but not helped.


What can possible Cause this Error ?
Supply Voltage / Ground and Diagnostic Cable checked.
Voltage on Desk 13,7 Volts.

Give it Components on PCP that Cause Error ?


Thank you




Edit 17.09.2023

I replace the 2 blue Powercaps ( 220 u-M ) and Error P1602 is gone but ECU not repaired.

I think its best to order used ECU and test this.

Other Components on PCB not in Warehouse.  

  

Edit 22.09.2023

New used ECU placed on Car and adapt Immo. Problem is gone and Car works fine.