Hondata

I have spent the better part of the last 2 months rewiring this car. We started the build in Oct 2019. Stripped down and fully rebuilt.
My supplied ground for the fan control is dead.
It appears that the circuit is dead is there any way to repair this?
OBD1 and through hole components were so much easier.

If the ECU is damaged, this cannot be repaired. Was a relay being used? You will need to replace the ECU.

I am pretty resourceful sending to a friend whom is an EE for a well known medical device company.
Has access to a Mantis microscope.
This is what I traced so far. Looks like the B6 trace goes through the layers of the board to this IC output.
Simple enough to replace this IC.
Not my first rodeo with .010” contacts.

That being said I already wired a manual switch as this is a race car.
But I wanted it to be an emergency not continuous use.

As far as the relay being used the car was hard wired with fans on with 12v switched when we got it.
I think I know why now.

Confirmed bad component.
Ordering from mouser for $1.50
Pin 4 is active at 5v using pin 3 as a ground.
The pins 5 and 6 are tied together as an output and should have continuity to pin 3 when active.

5v present
Pin 3 to 5/6 are not connected.

Wish me luck

PS pins 7/8 are the outputs for the fuel pump relay on the same TOP IC

Update:
IC replaced fans working now.