--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -7255,16 +7255,33 @@
     "alert_emails": ["telemetry-client-dev@mozilla.com"],
     "bug_numbers": [1318284],
     "expires_in_version": "never",
     "kind": "exponential",
     "high": 120000,
     "n_buckets": 20,
     "description": "Time needed (in ms) for a failed send of a Telemetry ping to the servers and getting a reply back."
   },
+  "TELEMETRY_SEND_FAILURE_TYPE" : {
+    "record_in_processes": ["main"],
+    "alert_emails": ["telemetry-client-dev@mozilla.com"],
+    "bug_numbers": [1367110],
+    "expires_in_version": "61",
+    "kind": "categorical",
+    "labels": [
+      "eOK",
+      "eRequest",
+      "eUnreachable",
+      "eChannelOpen",
+      "eRedirect",
+      "abort",
+      "timeout"
+    ],
+    "description": "Counts of the different ways sending a Telemetry ping can fail."
+  },
   "TELEMETRY_STRINGIFY" : {
     "record_in_processes": ["main", "content"],
     "alert_emails": ["telemetry-client-dev@mozilla.com"],
     "expires_in_version": "never",
     "kind": "exponential",
     "high": 3000,
     "n_buckets": 10,
     "description": "Time to stringify telemetry object (ms)"

--- a/toolkit/components/telemetry/TelemetrySend.jsm
+++ b/toolkit/components/telemetry/TelemetrySend.jsm
@@ -87,16 +87,26 @@ const SEND_TICK_DELAY = 1 * MS_IN_A_MINU
 // for the next ping sends. We increase the delay exponentially up to a limit of
 // SEND_MAXIMUM_BACKOFF_DELAY_MS.
 // This exponential backoff will be reset by external ping submissions & idle-daily.
 const SEND_MAXIMUM_BACKOFF_DELAY_MS = 120 * MS_IN_A_MINUTE;
 
 // The age of a pending ping to be considered overdue (in milliseconds).
 const OVERDUE_PING_FILE_AGE = 7 * 24 * 60 * MS_IN_A_MINUTE; // 1 week
 
+// Strings to map from XHR.errorCode to TELEMETRY_SEND_FAILURE_TYPE.
+// Echoes XMLHttpRequestMainThread's ErrorType enum.
+const XHR_ERROR_TYPE = [
+  "eOK",
+  "eRequest",
+  "eUnreachable",
+  "eChannelOpen",
+  "eRedirect",
+];
+
 function monotonicNow() {
   try {
     return Telemetry.msSinceProcessStart();
   } catch (ex) {
     // If this fails fall back to the (non-monotonic) Date value.
     return Date.now();
   }
 }
@@ -1102,17 +1112,23 @@ var TelemetrySendImpl = {
         .then(() => onCompletion(),
               (error) => {
                 this._log.error("_doPing - request success: " + success + ", error: " + error);
                 onCompletion();
               });
     };
 
     let errorhandler = (event) => {
-      this._log.error("_doPing - error making request to " + url + ": " + event.type);
+      let failure = event.type;
+      if (failure === "error") {
+        failure = XHR_ERROR_TYPE[request.errorCode];
+      }
+      Telemetry.getHistogramById("TELEMETRY_SEND_FAILURE_TYPE").add(failure);
+
+      this._log.error("_doPing - error making request to " + url + ": " + failure);
       onRequestFinished(false, event);
     };
     request.onerror = errorhandler;
     request.ontimeout = errorhandler;
     request.onabort = errorhandler;
 
     request.onload = (event) => {
       let status = request.status;