knock sensor check

[S_T_I_M_P_Y]

I get a knock sensor error with JDM Spoon ECU (PR3/PW0)

My car:
1990 Euro EE8 CRX VT (originally b16a VTEC)
now with JDM B16B type R
Currently running on original harness, ECU (b16a) and all engine ancillaries (injectors, in manifold etc).
NO KNOCK SENSOR.

With the original euro ECU it doesn't complain, but with JDM ECUs I get knock sensor error (as I don't have one...)

How do I disable the knock sensor check, or make it think there is a knock sensor giving right readings (what does it expect?)

Thanx

Asuka