The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  3  0  0  0  3  3  3 3a 6a+3  0  3 3a 6a+6  0  3
 0  0  3  0  0 3a+6 6a+6 3a  6 3a+6  3 3a+6 3a 3a+3 3a+6 3a+6
 0  0  0  3  0 3a+6  3 3a+3 3a+3 6a+6 6a+3 6a+6 6a+3 6a 6a+3 3a+6
 0  0  0  0  3 6a+6  6 6a+3  3  3 3a 3a  3 3a+3 3a+6 3a+6

generates a code of length 16 over GR(81,9) who´s minimum homogenous weight is 90.

Homogenous weight enumerator: w(x)=1x^0+208x^90+1576x^99+3992x^108+8912x^117+17792x^126+472392x^128+17544x^135+9024x^144

The gray image is a code over GF(9) with n=144, k=6 and d=90.
This code was found by Heurico 1.16 in 15.2 seconds.