Исходный код метода:
$this->language->load('payment/cheque');
$this->load->model('checkout/order');
$comment = $this->language->get('text_payable') . "\n";
$comment .= $this->config->get('cheque_payable') . "\n\n";
$comment .= $this->language->get('text_address') . "\n";
$comment .= $this->config->get('config_address') . "\n\n";
$comment .= $this->language->get('text_payment') . "\n";
$this->model_checkout_order->confirm($this->session->data['order_id'], $this->config->get('cheque_order_status_id'), $comment, true);