The generator matrix

 1  0  1  1  1  1  1  1  1  0  1  1
 0  1  1  a 3a+3  0 2a+3  a a+1  1  a  a
 0  0 2a+2  0  0  0  2  0  2  2 2a 2a
 0  0  0  2  0  0 2a+2  2  2 2a+2  0 2a
 0  0  0  0 2a+2  0  2 2a+2  0 2a+2 2a  2
 0  0  0  0  0  2 2a+2 2a+2  2 2a 2a  0

generates a code of length 12 over GR(16,4) who´s minimum homogenous weight is 24.

Homogenous weight enumerator: w(x)=1x^0+378x^24+972x^28+3072x^30+3087x^32+18432x^34+6504x^36+27648x^38+4878x^40+396x^44+168x^48

The gray image is a code over GF(4) with n=48, k=8 and d=24.
This code was found by Heurico 1.16 in 1.81 seconds.