The generator matrix

 1  0  0  0  1  3  1  1  6  1  1  6
 0  1  0  0  6  1  3  5  1  3  1  1
 0  0  1  0  6  5  7  4  3  4  6  5
 0  0  0  1  7  6  1  6  1  0  4  7

generates a code of length 12 over Z9 who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+438x^18+1422x^21+2538x^24+2018x^27+144x^30

The gray image is a code over GF(3) with n=36, k=8 and d=18.
This code was found by Heurico 1.13 in 0.032 seconds.