Follow-up.

Checked the continuity on all ABS sensors. OK
Checked ABS sensors output while rolling the car. OK
Checked ABS light again. Still on.

Removed the battery, cleaned the terminals(only a nominal bit of corrosion)
Removed ABS brain, ECU and fuel injection relay.
Loosened and tightened the wires at the buse and ground wire at front strut tower.

ABS light is off.

Tinker