Registration method is not done PHP

I hope someone can help me with the following detail. First of all put the code. It happens that, once I click on save, it does not mark me an error, but rather that the browser stays in the controller -register- and does not do more. I do not know what detail I should have around there. Thanks for taking the time to review my problem.

Model

    public function guardarC(
    $CURP, $nombre, $ap_P, $ap_M, $num_tel, $id_localidad, $id_colonia, 
    $referencia) {

    $ciudadano = array(
        'CURP'         => $CURP,
        'nombre'       => $nombre,
        'ap_P'         => $ap_P,
        'ap_M'         => $ap_M,
        'num_tel'      => $num_tel,
        'id_localidad' => $id_localidad,
        'id_colonia'   => $id_colonia,
        'referencia'   => $referencia,
    );
    $this->db->insert('cat_ciudadanos', $ciudadano);
}

Driver

    public function registrar()
{
    if ($this->input->post('submit')) {

        $this->form_validation->set_rules('CURP', 'CURP', 'required');
        $this->form_validation->set_rules('nombre', 'nombre', 'required');
        $this->form_validation->set_rules('ap_P', 'ap_P', 'required');
        $this->form_validation->set_rules('ap_M', 'ap_M', 'required');
        $this->form_validation->set_rules('num_tel', 'num_tel', 'required');
        $this->form_validation->set_rules('id_localidad', 'id_localidad', 'required');
        $this->form_validation->set_rules('id_colonia', 'id_colonia', 'required');
        $this->form_validation->set_rules('referencia', 'referencia', 'required');

        if ($this->form_validation->run() == true) {
            $CURP         = $_POST['CURP'];
            $nombre       = $_POST['nombre'];
            $ap_P         = $_POST['ap_P'];
            $ap_M         = $_POST['ap_M'];
            $num_tel      = $_POST['num_tel'];
            $id_localidad = $_POST['id_localidad'];
            $id_colonia   = $_POST['id_colonia'];
            $referencia   = $_POST['referencia'];

            $datos = $this->Registros_model->guardarC(
                $CURP,
                $nombre,
                $ap_P,
                $ap_M,
                $num_tel,
                $id_localidad,
                $id_colonia,
                $referencia
            );

            redirect('ayuntamiento/registroC', 'refresh');
        }
    }
}

Vista

<div class="container">
<form id="form" name="form" method="POST" action="<?php echo base_url(); ?>ayuntamiento/registrar">
<div class="row">
    <div class="col-md-6 col-md-offset-3">
        <div class="form-group">
            <label for="CURP">C U R P</label>
            <input class="form-control" type="text" id="CURP" placeholder="C U R P">
        </div>
    </div>
</div>

<div class="row">
    <div class="col-md-6 col-md-offset-3">
         <div class="form-group">
             <label for="nombre">Nombre</label>
             <input class="form-control" type="text" id="nombre" placeholder="Nombre (s)">
         </div>
    </div>
</div>

<div class="row">
    <div class="col-md-6 col-md-offset-3">
        <div class="form-group">
            <label for="ap_P">Primer Apellido</label>
            <input class="form-control" type="text" id="ap_P" placeholder="Apellido Paterno">
        </div>
    </div>
</div>

<div class="row">
    <div class="col-md-6 col-md-offset-3">
        <div class="form-group">
            <label for="ap_M">Segundo Apellido</label>
            <input class="form-control" type="text" id="ap_M" placeholder="Apellido Materno">
        </div>
    </div>
 </div>

<div class="row">
    <div class="col-md-6 col-md-offset-3">
        <div class="form-group">
            <label for="telefono">Numero Telefonico</label>
            <input class="form-control" type="text" id="num_tel" placeholder="Numero Telefonico">
        </div>
    </div>
</div>

<div class="row">
    <div class="col-md-6 col-md-offset-3">
        <div class="form-group">
            <label>Dirección</label>
            <br>
            <select  class="form-control" id="id_localidad" name="id_localidad" style="background-color: #A9A9A9">
                <option value="0">Localidades</option>
                <?php foreach ($localidades as $i) {?>
                 <option value="<?php echo $i->id_localidad; ?>"><?php echo $i->nombre; ?></option>;
                <?php }?>
            </select>
        </div>
    </div>
</div>

<div class="row">
    <div class="col-md-6 col-md-offset-3">
        <div class="form-group">
            <select class="form-control" id="id_colonia" name="id_colonia" style="background-color: #A9A9A9">
                <option value="0">Colonias</option>
                <?php foreach ($colonias as $i) {?>
                 <option value="<?php echo $i->id_colonia; ?>"><?php echo $i->nombre; ?></option>;
                <?php }?>
            </select>
        </div>
    </div>
</div>

<div class="row">
    <div class="col-md-6 col-md-offset-3">
        <div class="form-group">
            <label for="referencia">Referencia</label>
            <textarea class="form-control" rows="5" id="referencia"></textarea>
        </div>
    </div>
</div>

    <div class="container">
        <button type="submit" class="btn btn-primary center-block">
        <span class="glyphicon glyphicon-floppy-disk" aria-hidden="true"></span>
        Guardar
        </button>
    </div>
</form>