J1939 Parameter In (JPIN) 2 bits length

True/False signals for J1939 are two bits for the error check. 0=False 1=True, 2=not used, 3=error.

Expected with JPIN 2 bits, i shall fill a numeric value, not a boolean, doesn't it ?

With JPIN 2 bits, i shall connect a state parameter to JPIN : actually it is impossible due to JPIN 2 bits is actually a boolean variable
With JPIN 4 bits, i can connect a state parameter to JPIN : the JPIN 4 bits is a numerical value.

If you turn off the j1939 error check - then it will become numeric.

Thank for responses