1Departamento de Ci^encias e Engenharias Universidade Regional Integrada URI, Frederico Westphalen, RS, Brazil. Email: arpasi@fw.uri.br
2Departamento de Matemática Universidad de Tarapacá, Casilla 7D Arica, Chile Email: ychalco@uta.cl
We consider the trellis section of a time invariant group code and show that when this trellis section is a non abelian finite p group, and the information set is the ad ditive group of the integers module p, then the group code can not be controllable.