The generator matrix

 1  0  0  0  1  1  1  1  1  1
 0  1  0  0  1  0  1  a  a  X
 0  0  1  0 a+1  1  a  a  1 (a+1)X+1
 0  0  0  1  1 a+1 a+1  a  1 X+a+1
 0  0  0  0 (a+1)X  X aX  X  0 (a+1)X

generates a code of length 10 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+228x^18+360x^19+90x^20+768x^21+2736x^22+1440x^23+3828x^24+6912x^25+12312x^26+18864x^27+22068x^28+20736x^29+46128x^30+48672x^31+33147x^32+20736x^33+18468x^34+4392x^35+210x^36+48x^40

The gray image is a linear code over GF(4) with n=40, k=9 and d=18.
This code was found by Heurico 1.16 in 7.93 seconds.