The ATC lights is finally get steady on. I checked with AcomDiagnostic it's says PS2 brake demand pressure sensor circuit is faulty. Grounded or shorted to the +5 volt. On ABS module socket X4 pins 1, 4, 6. Tracing circuit on Volvo electrical diagram to figure out where sensor is but diagram says it's not sensor it's valve Y100.
How to find this sensor?