The generator matrix

 1  0  0  1  1  1  0  1  1  1  1  0  2  0  1  0  1  2  1  2  1
 0  1  0  1  0  1  1  0  0  1  1  1  1  2  0  0  1  1  0  1  1
 0  0  1  1  1  0  1  0  1  1  0  2  1  1  3  1  1  3  0  1  1
 0  0  0  2  0  0  0  0  0  0  0  2  0  2  2  0  0  2  0  0  2
 0  0  0  0  2  0  0  0  0  0  0  2  2  0  2  0  0  0  2  0  2
 0  0  0  0  0  2  0  0  0  0  0  0  2  2  2  0  2  2  0  0  0
 0  0  0  0  0  0  2  0  0  0  0  0  2  0  0  2  2  0  2  0  2
 0  0  0  0  0  0  0  2  0  0  0  0  0  0  2  2  0  2  2  2  0
 0  0  0  0  0  0  0  0  2  0  0  2  2  0  0  0  2  2  2  2  2
 0  0  0  0  0  0  0  0  0  2  0  2  0  2  2  2  0  0  0  2  0
 0  0  0  0  0  0  0  0  0  0  2  0  2  2  2  2  0  0  0  0  2

generates a code of length 21 over Z4 who´s minimum homogenous weight is 12.

Homogenous weight enumerator: w(x)=1x^0+148x^12+316x^14+1366x^16+2176x^18+4348x^20+3672x^22+2784x^24+992x^26+524x^28+12x^30+41x^32+4x^36

The gray image is a code over GF(2) with n=42, k=14 and d=12.
This code was found by Heurico 1.16 in 3.18 seconds.