The generator matrix

 1  0  0  0  1  1  1  1  1  1  1  1  3
 0  1  0  0  6  1  7  0  4  6  7  8  1
 0  0  1  0  7  1  5  6  5  8  3  1  0
 0  0  0  1  5  3  8  5  3  1  2  0  1

generates a code of length 13 over Z9 who´s minimum homogenous weight is 20.

Homogenous weight enumerator: w(x)=1x^0+390x^20+260x^21+780x^23+702x^24+1800x^26+728x^27+1248x^29+494x^30+156x^32+2x^39

The gray image is a code over GF(3) with n=39, k=8 and d=20.
This code was found by Heurico 1.13 in 486 seconds.