The generator matrix

 1  0  0  0  1  1  1  2  1  2  1 X+2  X  1  1 X+2  1 X+2  0  1  1
 0  1  0  0  0  1  1  1 X+3  1  2  X  X  X X+3  2  2  1  1  0  X
 0  0  1  0  1  1  X X+1  X X+3  0  1  1 X+3 X+1  X X+3  X  3  X  X
 0  0  0  1  1  0 X+1  1  X  2 X+3  3 X+3  0  3  1 X+1 X+1 X+3  2 X+2
 0  0  0  0  X  2  0  2  X  X X+2  0 X+2  X  2 X+2  2  2 X+2  X X+2

generates a code of length 21 over Z4[X]/(X^2+2,2X) who´s minimum homogenous weight is 15.

Homogenous weight enumerator: w(x)=1x^0+72x^15+310x^16+710x^17+1281x^18+1826x^19+2412x^20+2954x^21+2644x^22+1908x^23+1291x^24+626x^25+233x^26+82x^27+18x^28+14x^29+2x^30

The gray image is a code over GF(2) with n=84, k=14 and d=30.
This code was found by Heurico 1.16 in 2.16 seconds.