The generator matrix

 1  0  1
 0  1 a^7*X
 0  0 a^7*X+1

generates a code of length 3 over F9[X]/(X^2) who´s minimum homogenous weight is 8.

Homogenous weight enumerator: w(x)=1x^0+216x^8+24x^9+15552x^16+3456x^17+192x^18+373248x^24+124416x^25+13824x^26+512x^27

The gray image is a linear code over GF(9) with n=27, k=6 and d=8.
This code was found by Heurico 1.16 in 0.153 seconds.