Unplug ONE end (either end - doesn't matter) of the diode near to the ABS fuses/relays (grey rubber cylinder 2 inches long, brown/red wire one end, blue/green wire the other).

With ECU unplugged and ignition off, temporarily join ECU connector terminals 2 and 8 with a jumper wire. With the ignition on, what is the voltage between terminals 1 and 3 ?