Update Keterangan Error - - E-Commerce Reseller konsep Marketplace dengan Codeigniter +

Assalam,.. bantu jawab mas errornya semoga bermanfaat...
coba ganti mas di bagian controllers/reseller/
 
function keterangan(){
		cek_session_reseller();
		if (isset($_POST['submit'])){
			$cek = $this->model_app->view_where('rb_keterangan',array('id_reseller'=>$this->session->id_reseller))->num_rows();
			if ($cek>=1){
				$data1 = array('keterangan'=>$this->input->post('a'));
				$where = array('id_keterangan' => $this->input->post('id'),'id_reseller'=>$this->session->id_reseller);
				$this->model_app->update('rb_keterangan', $data1, $where);
			}else{
				$data1 = array('id_reseller'=>$this->session->id_reseller,
							   'keterangan'=>$this->input->post('a'),
							   'tanggal_posting'=>date('Y-m-d H:i:s'));
				$this->model_app->insert('rb_keterangan',$data); //ganti $data dengan $data1 << ini yg buat error untuk insert sepertinya mas 
			}
			redirect($this->uri->segment(1).'/keterangan');
		}else{
			$data['record'] = $this->model_app->edit('rb_keterangan',array('id_reseller'=>$this->session->id_reseller))->row_array();
			$this->template->load($this->uri->segment(1).'/template',$this->uri->segment(1).'/mod_keterangan/view_keterangan',$data);
		}
	}
 

Assalam,.. Baik, akan dicoba dan terimakasih atas responnya :) 

Assalam,.. sama2 pak semoga membantu