The generator matrix

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

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

Homogenous weight enumerator: w(x)=1x^0+76x^12+8x^13+28x^14+64x^15+310x^16+224x^17+148x^18+448x^19+448x^20+560x^21+464x^22+448x^23+168x^24+224x^25+320x^26+64x^27+20x^28+8x^29+52x^30+1x^32+12x^34

The gray image is a code over GF(2) with n=42, k=12 and d=12.
This code was found by Heurico 1.16 in 0.26 seconds.