diff --git a/dom/mobileconnection/tests/marionette/head.js b/dom/mobileconnection/tests/marionette/head.js
index e95939fbb6fd..e06a59103940 100644
--- a/dom/mobileconnection/tests/marionette/head.js
+++ b/dom/mobileconnection/tests/marionette/head.js
@@ -36,7 +36,8 @@ function runEmulatorCmdSafe(aCommand) {
     --_pendingEmulatorCmdCount;
 
     ok(true, "Emulator response: " + JSON.stringify(aResult));
-    if (Array.isArray(aResult) && aResult[0] === "OK") {
+    if (Array.isArray(aResult) &&
+        aResult[aResult.length - 1] === "OK") {
       deferred.resolve(aResult);
     } else {
       deferred.reject(aResult);
@@ -450,6 +451,51 @@ function setEmulatorRoamingAndWait(aRoaming) {
     .then(() => doSetAndWait("data", aRoaming));
 }
 
+/**
+ * Get GSM location emulation.
+ *
+ * Fulfill params:
+ *   { lac: <lac>, cid: <cid> }
+ * Reject params:
+ *   result -- an array of emulator response lines.
+ *
+ * @return A deferred promise.
+ */
+function getEmulatorGsmLocation() {
+  let cmd = "gsm location";
+  return runEmulatorCmdSafe(cmd)
+    .then(function(aResults) {
+      // lac: <lac>
+      // ci: <cid>
+      // OK
+      is(aResults[0].substring(0,3), "lac", "lac output");
+      is(aResults[1].substring(0,2), "ci", "ci output");
+
+      let lac = parseInt(aResults[0].substring(5));
+      lac = (lac < 0 ? 65535 : lac);
+      let cid = parseInt(aResults[1].substring(4));
+      cid = (cid < 0 ? 268435455 : cid);
+
+      return { lac: lac, cid: cid };
+    });
+}
+
+/**
+ * Set GSM location emulation.
+ *
+ * Fulfill params: (none)
+ * Reject params: (none)
+ *
+ * @param aLac
+ * @param aCid
+ *
+ * @return A deferred promise.
+ */
+function setEmulatorGsmLocation(aLac, aCid) {
+  let cmd = "gsm location " + aLac + " " + aCid;
+  return runEmulatorCmdSafe(cmd);
+}
+
 let _networkManager;
 
 /**
diff --git a/dom/mobileconnection/tests/marionette/test_mobile_voice_location.js b/dom/mobileconnection/tests/marionette/test_mobile_voice_location.js
index 14374fe74d5d..eb977b5afc64 100644
--- a/dom/mobileconnection/tests/marionette/test_mobile_voice_location.js
+++ b/dom/mobileconnection/tests/marionette/test_mobile_voice_location.js
@@ -1,33 +1,17 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
-MARIONETTE_TIMEOUT = 20000;
-MARIONETTE_HEAD_JS = "mobile_header.js";
-
-function setEmulatorGsmLocation(lac, cid) {
-  emulatorHelper.sendCommand("gsm location " + lac + " " + cid);
-}
-
-function waitForVoiceChangeEvent(callback) {
-  mobileConnection.addEventListener("voicechange", function onvoicechange() {
-    mobileConnection.removeEventListener("voicechange", onvoicechange);
-
-    if (callback && typeof callback === "function") {
-      callback();
-    }
-  });
-}
-
-/* Test Initial Voice Cell Location Info */
-taskHelper.push(function testInitialVoiceCellLocationInfo() {
-  log("Test initial voice location info");
+MARIONETTE_TIMEOUT = 60000;
+MARIONETTE_HEAD_JS = "head.js";
 
+function verifyVoiceCellLocationInfo(aLac, aCid) {
   let cell = mobileConnection.voice.cell;
   ok(cell, "location available");
+
   // Initial LAC/CID. Android emulator initializes both value to
   // 0xffff/0xffffffff.
-  is(cell.gsmLocationAreaCode, 65535, "check voice.cell.gsmLocationAreaCode");
-  is(cell.gsmCellId, 268435455, "check voice.cell.gsmCellId");
+  is(cell.gsmLocationAreaCode, aLac, "check voice.cell.gsmLocationAreaCode");
+  is(cell.gsmCellId, aCid, "check voice.cell.gsmCellId");
   is(cell.cdmaBaseStationId, -1, "check voice.cell.cdmaBaseStationId");
   is(cell.cdmaBaseStationLatitude, -2147483648,
      "check voice.cell.cdmaBaseStationLatitude");
@@ -35,54 +19,31 @@ taskHelper.push(function testInitialVoiceCellLocationInfo() {
      "check voice.cell.cdmaBaseStationLongitude");
   is(cell.cdmaSystemId, -1, "check voice.cell.cdmaSystemId");
   is(cell.cdmaNetworkId, -1, "check voice.cell.cdmaNetworkId");
-
-  taskHelper.runNext();
-});
+}
 
 /* Test Voice Cell Location Info Change */
-taskHelper.push(function testVoiceCellLocationUpdate() {
+function testVoiceCellLocationUpdate(aLac, aCid) {
   // Set emulator's lac/cid and wait for 'onvoicechange' event.
-  function doTestVoiceCellLocation(lac, cid, callback) {
-    log("Test cell location with lac=" + lac + " and cid=" + cid);
+  log("Test cell location with lac=" + aLac + " and cid=" + aCid);
 
-    waitForVoiceChangeEvent(function() {
-      let cell = mobileConnection.voice.cell;
-      is(cell.gsmLocationAreaCode, lac, "check voice.cell.gsmLocationAreaCode");
-      is(cell.gsmCellId, cid, "check voice.cell.gsmCellId");
-      // cdma information won't change.
-      is(cell.cdmaBaseStationId, -1, "check voice.cell.cdmaBaseStationId");
-      is(cell.cdmaBaseStationLatitude, -2147483648,
-         "check voice.cell.cdmaBaseStationLatitude");
-      is(cell.cdmaBaseStationLongitude, -2147483648,
-         "check voice.cell.cdmaBaseStationLongitude");
-      is(cell.cdmaSystemId, -1, "check voice.cell.cdmaSystemId");
-      is(cell.cdmaNetworkId, -1, "check voice.cell.cdmaNetworkId");
+  let promises = [];
+  promises.push(waitForManagerEvent("voicechange"));
+  promises.push(setEmulatorGsmLocation(aLac, aCid));
+  return Promise.all(promises)
+    .then(() => verifyVoiceCellLocationInfo(aLac, aCid));
+}
 
-      if (callback && typeof callback === "function") {
-        callback();
-      }
+startTestCommon(function() {
+  return getEmulatorGsmLocation()
+    .then(function(aResult) {
+      log("Test initial voice location info");
+      verifyVoiceCellLocationInfo(aResult.lac, aResult.cid);
+
+      return Promise.resolve()
+        .then(() => testVoiceCellLocationUpdate(100, 100))
+        .then(() => testVoiceCellLocationUpdate(2000, 2000))
+
+        // Reset back to initial values.
+        .then(() => testVoiceCellLocationUpdate(aResult.lac, aResult.cid));
     });
-
-    setEmulatorGsmLocation(lac, cid);
-  }
-
-  let testData = [
-    {lac: 100, cid: 100},
-    {lac: 2000, cid: 2000},
-    // Reset lac/cid to default value.
-    {lac: 65535, cid: 268435455}
-  ];
-
-  // Run all test data.
-  (function do_call() {
-    let next = testData.shift();
-    if (!next) {
-      taskHelper.runNext();
-      return;
-    }
-    doTestVoiceCellLocation(next.lac, next.cid, do_call);
-  })();
 });
-
-// Start test
-taskHelper.runNext();