The generator matrix

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

generates a code of length 15 over Z3[X]/(X^2) who´s minimum homogenous weight is 24.

Homogenous weight enumerator: w(x)=1x^0+600x^24+1430x^27+2250x^30+1920x^33+360x^36

The gray image is a linear code over GF(3) with n=45, k=8 and d=24.
This code was found by Heurico 1.16 in 0.109 seconds.