[Mustang5L5]

I have an A9L apart that needs new capacitors. While i'm here, i wanted to learn a bit more about the inner workings of the A9L. I've identified all of the transistors and what they control, but am looking to see if anyone knows what component on this board is responsible for the 5V reference voltage.

I do know that the top-most transistor in the bank on the right side of the above image seems to be a gate for VREF to pin 26 on the ECU. But my question is what generates the 5V Vref? If this was bad on an A9x, what component would be replaced?

 

[Mustang5L5]

Oh BTW,

Fuel pump control, pin 22 is this transistor here circled in red. So if you have a constantly running fuel pump and replacing the capacitors doesn’t solve it, this is the one to investigate.

 

[Mustang5L5]

Interesting.

Thanks for the info

 

[Mustang5L5]

Any ETA on when something would be available?

 

[Mustang5L5]

The number on the fuel pump transistor is 04S74

I haven’t spent much time trying to find what the modern equivalent would be. Struggled to find a data-sheet. Most of the ECU issues I’ve seen have always been capacitors.