The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  X  X  1  X  X  X  X
 0  3  6  0  3  6  0  3  6  0  3  3  6  6  0  3  6  0

generates a code of length 18 over Z9[X]/(X^2+6,3X) who´s minimum homogenous weight is 36.

Homogenous weight enumerator: w(x)=1x^0+74x^36+6x^42

The gray image is a code over GF(3) with n=162, k=4 and d=108.
This code was found by Heurico 1.16 in 0.00106 seconds.