The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  X 2X  0 2X^2+X 2X  0 2X^2+X 2X X^2 2X^2+X 2X  0 X^2 2X^2+X X^2+2X  X 2X^2+2X
 0  0 X^2  0  0  0 X^2 2X^2 X^2 X^2 2X^2 X^2 X^2 X^2  0  0  0 X^2
 0  0  0 X^2  0 X^2 X^2 2X^2 X^2  0 X^2 2X^2 2X^2  0 2X^2  0 2X^2  0
 0  0  0  0 2X^2 2X^2 X^2 2X^2 2X^2 X^2 2X^2  0  0  0  0 2X^2 2X^2 2X^2

generates a code of length 18 over Z3[X]/(X^3) who´s minimum homogenous weight is 30.

Homogenous weight enumerator: w(x)=1x^0+270x^30+288x^33+5370x^36+468x^39+144x^42+18x^48+2x^54

The gray image is a linear code over GF(3) with n=162, k=8 and d=90.
This code was found by Heurico 1.16 in 40.4 seconds.