Unable to post the data from view to controller in Yii2

I am working on Yii2. I have a gridview with checkbox and on a button click I am redirecting it to an action controller using ajax.

 <?= Html::a('Disconnect', ['dco'], ['class' => 'btn btn-success', 'id'=>'dco']) ?>

<?php Pjax::begin(); ?>    
        <?= GridView::widget([
    'dataProvider' => $dataProvider,
    'filterModel' => $searchModel,
    'columns' => [


        ['class' => 'yii\grid\CheckboxColumn', 'checkboxOptions' => function($d) {
            return ['value' => $d['msn']];
        }],


        'ref_no',
        'dept_code:ntext',
        'dept_name:ntext',

        'allowed_units',
        'msn',

        'units_consumed',
        [
            'label' => 'Disconnected',
            'attribute' => 'disconnected',
            'format'=>'raw',
            'contentOptions' => ['style'=>'text-align:center'],
            'value' => function($model){
                return $model->disconnected == 1 ? '<span class="glyphicon glyphicon-ok text-success"></span>' : '<span class="glyphicon glyphicon-remove text-danger"></span>';
            },
            'filter' => Html::activeDropDownList($searchModel, 'disconnected', [''=>'All','1'=>'Yes','0'=>'No'], ['class' => 'form-control']),
        ],

        'diconnected_at',
        'reconnected_at',
        'active_energy_total_m',


        ['class' => 'yii\grid\ActionColumn'],
    ],
]); ?>
<?php Pjax::end(); ?>

JS

<?php

$DCOurl = Url::toRoute(['/hecolog/dco']);

$script = <<< JS
$(document).ready(function () {  



 //DCO 
 $('#dco').on('click',function(e) {


       e.preventDefault();    
 var strValue = "";        
    $('input[name="selection[]"]:checked').each(function() {

    if(strValue!=="")
        {
        strValue = strValue + " , " + this.value;

        }
    else 
       strValue = this.value;     

});       

 $.ajax({
    url: '$DCOurl',
    type: 'POST',
    dataType: 'json',
    data: {data:strValue},         
    success: function(data) {
       alert(data);
    }
 });


 });
});
JS;
$this->registerJs($script, static::POS_END);
?>

But when I click on the disconnect button it doesn't redirect to my controller. In console it gives me Not Found (#404): Page not found.

Update 1

I have updated the ajax call like below

$.ajax({
    url: $DCOurl, // removed the inverted commas ''
    type: 'POST',
    dataType: 'json',
    data: {data:strValue},         
    success: function(data) {
       alert(data);
    }
 });

Controller

 public function actionDco()
{
    if(Yii::$app->request->isAjax && Yii::$app->request->post())
    {
        $data = explode(',',$_POST['data']);

        var_dump($data);
        die();
    }
    else{
        $this->redirect('index');
    }




}

After updating the code as suggested I am able to go into my controller but still not able to get the data

In console I am getting error Uncaught SyntaxError: Invalid regular expression flags

I must be doing something wrong which I am not understanding

Any help would be highly appreciated.

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