The generator matrix

 1  0  0  0  1  1  1  4  1  1  8  2  1  2  6 10  1  1
 0  1  0  0  2  9  5  1  4  9  6  1  8  1  2  1 10  0
 0  0  1  0  3  1  6  7  3  1  1  7  7  6  1 11 15  0
 0  0  0  1  1  4  3  3  2  3  5  2  4  5 10 13  4  0
 0  0  0  0  4  8  0  8  0  4  4 12 12  4  0  8  8  8

generates a code of length 18 over Z16 who´s minimum homogenous weight is 12.

Homogenous weight enumerator: w(x)=1x^0+52x^12+574x^13+2413x^14+8984x^15+25795x^16+55870x^17+74546x^18+56192x^19+25856x^20+8890x^21+2302x^22+552x^23+104x^24+10x^25+2x^26+1x^30

The gray image is a code over GF(2) with n=144, k=18 and d=48.
This code was found by Heurico 1.16 in 99.2 seconds.