Careful when buying your engine: dents on ECU

[George_R]

So a customer sent me this ECU for security off, and I noted the dent on ECU case

No wonder this unit would not start the engine even after security removal. Turned out that it could not detect crank angle sensor signal. So I took a thorough look inside

This SMD resistor easily broken into 3 pieces right when I touched it with soldering iron

Replaced it with closest part I could find (2 resistors of double resistance and half tolerated power connected in parallel)

note how the problem corresponds to the dent on ECU case

So overall if you see dents on ECU , there's possibility of weird things happening inside which are NOT apparently seen when you open the case

 

[cribbj]

Great diagnosis & fix, George; thanks for posting!

 

[George_R]

Thanks!
In fact, CAS simulator is simple but very useful tool for things like this. If someone wants to build one, PM me for schematic and firmware

 

[MaxFP]

Sadly i learn't this the hard way and had to replace the ECU.

The ecu was "dead" only would turn on M-rel but not even the check light would come on.

 

[George_R]

Hi Max, good to hear from you! There are much more reasons why ECU would not start the engine. Aging can be a problem too, even if ECU looks ok mechanically

 

[MaxFP]

Hi Max, good to hear from you! There are much more reasons why ECU would not start the engine. Aging can be a problem too, even if ECU looks ok mechanically

Yeah well it had leaking caps.. a smashed one (yes i think it got under an engine or something) and the board was already curved even taking it apart. so it sat like that for years probably.


Now its up and running.