The generator matrix

1 0 0 0 0 0 0 1 1 1 1 1 1 2 0 2 1 1 2 1 1
0 1 0 0 0 0 0 0 0 0 0 0 0 1 1 1 2 2 1 3 2
0 0 1 0 0 0 0 0 1 1 2 3 0 1 1 2 3 0 2 1 0
0 0 0 1 0 0 0 0 1 2 0 1 3 3 1 2 1 3 0 0 0
0 0 0 0 1 0 0 0 1 3 3 0 1 3 3 1 3 1 1 1 0
0 0 0 0 0 1 0 1 0 1 3 1 3 1 2 1 1 1 3 3 1
0 0 0 0 0 0 1 1 3 1 2 2 1 3 2 1 2 2 0 3 0
0 0 0 0 0 0 0 2 2 0 2 0 0 2 0 0 2 2 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+110x^12+186x^13+501x^14+740x^15+1232x^16+1806x^17+2512x^18+3402x^19+3812x^20+4178x^21+3754x^22+3330x^23+2644x^24+1834x^25+1320x^26+686x^27+382x^28+188x^29+105x^30+34x^31+11x^32

The gray image is a code over GF(2) with n=42, k=15 and d=12.
This code was found by Heurico 1.10 in 6.46 seconds.