Peer Manager Unknown CONN_SEC Error Number

Question

I'm using an Nrf52 with S132v3.0
I'm using Peer Manager to manage pairing and bonding.
I'm running as a central connecting to a peripheral (iOS/Android peripheral). 
 I'm using "out of the box" peer management code using the following link from the SDK as an example.
 infocenter.nordicsemi.com/index.jsp 
 Most of the time the connection/pairing/bonding works just fine. On occasion I've experienced PM_EVT_CONN_SEC_FAILED. 
 Below is my switch statement broken up for debug purposes. 
 switch (p_evt->params.conn_sec_failed.error)
 {
 case PM_CONN_SEC_ERROR_PIN_OR_KEY_MISSING:
 // Rebond if one party has lost its keys.
 err_code = pm_conn_secure(p_evt->conn_handle, true);
 if (err_code != NRF_ERROR_INVALID_STATE)
 {
 APP_ERROR_CHECK(err_code);
 }
 break;//PM_CONN_SEC_ERROR_PIN_OR_KEY_MISSING
 
 case PM_CONN_SEC_ERROR_MIC_FAILURE:
 NRF_LOG_DEBUG("error: PM_CONN_SEC_ERROR_MIC_FAILURE");
 sd_ble_gap_disconnect(p_evt->conn_handle, BLE_HCI_AUTHENTICATION_FAILURE);
 break;//PM_CONN_SEC_ERROR_MIC_FAILURE

 case PM_CONN_SEC_ERROR_DISCONNECT :
 NRF_LOG_DEBUG("error: PM_CONN_SEC_ERROR_DISCONNECT ");
 sd_ble_gap_disconnect(p_evt->conn_handle, BLE_HCI_AUTHENTICATION_FAILURE);
 break;//PM_CONN_SEC_ERROR_DISCONNECT

 case PM_CONN_SEC_ERROR_SMP_TIMEOUT:
 NRF_LOG_DEBUG("error: PM_CONN_SEC_ERROR_SMP_TIMEOUT");
 sd_ble_gap_disconnect(p_evt->conn_handle, BLE_HCI_AUTHENTICATION_FAILURE);
 break;//PM_CONN_SEC_ERROR_SMP_TIMEOUT
 
 default:
 /* Close the connection and move on */
 sd_ble_gap_disconnect(p_evt->conn_handle, BLE_HCI_AUTHENTICATION_FAILURE);
 break;
 }
 
 The error I'm getting is "Unknown" with an error ID of 0x0001. 
Looking at the documentation: infocenter.nordicsemi.com/index.jsp 
 The only valid error IDs are 0x6, 0x3D, 0x100 ,0x101. Has anyone seen 0x0001? Any idea what it means?

Jørn · Accepted Answer

I have conferred with a colleague.
The error you are getting is most likely a BLE_GAP_SEC_STATUS_TIMEOUT, which is a timeout that can occur during pairing when the device you are trying to pair to do not respond within a predefined time. This time is defined in the Bluetooth specification and is set to 30 seconds.
The normal response to this error is to retry the pairing process.