diff --git a/src/java/com/android/ims/ImsCall.java b/src/java/com/android/ims/ImsCall.java
index 760e5e8..e32103e 100644
--- a/src/java/com/android/ims/ImsCall.java
+++ b/src/java/com/android/ims/ImsCall.java
@@ -1628,6 +1628,7 @@
             // Make a copy of the current ImsCallProfile and modify it to enable RTT
             Parcel p = Parcel.obtain();
             mCallProfile.writeToParcel(p, 0);
+            p.setDataPosition(0);
             ImsCallProfile requestedProfile = new ImsCallProfile(p);
             requestedProfile.mMediaProfile.setRttMode(ImsStreamMediaProfile.RTT_MODE_FULL);
 
@@ -3077,6 +3078,7 @@
         public void callSessionRttModifyRequestReceived(ImsCallSession session,
                 ImsCallProfile callProfile) {
             ImsCall.Listener listener;
+            logi("callSessionRttModifyRequestReceived");
 
             synchronized(ImsCall.this) {
                 listener = mListener;
@@ -3101,6 +3103,7 @@
         public void callSessionRttModifyResponseReceived(int status) {
             ImsCall.Listener listener;
 
+            logi("callSessionRttModifyResponseReceived");
             synchronized(ImsCall.this) {
                 listener = mListener;
             }
diff --git a/src/java/com/android/ims/ImsManager.java b/src/java/com/android/ims/ImsManager.java
index ad8d11b..0a0eb24 100644
--- a/src/java/com/android/ims/ImsManager.java
+++ b/src/java/com/android/ims/ImsManager.java
@@ -245,9 +245,12 @@
 
     /**
      * Returns the user configuration of Enhanced 4G LTE Mode setting for slot. If the option is
-     * not editable ({@link CarrierConfigManager#KEY_EDITABLE_ENHANCED_4G_LTE_BOOL} is false),
-     * this method will return default value specified by
+     * not editable ({@link CarrierConfigManager#KEY_EDITABLE_ENHANCED_4G_LTE_BOOL} is false), or
+     * the setting is not initialized, this method will return default value specified by
      * {@link CarrierConfigManager#KEY_ENHANCED_4G_LTE_ON_BY_DEFAULT_BOOL}.
+     *
+     * Note that even if the setting was set, it may no longer be editable. If this is the case we
+     * return the default value.
      */
     public boolean isEnhanced4gLteModeSettingEnabledByUser() {
         int setting = SubscriptionManager.getIntegerSubscriptionProperty(
@@ -546,7 +549,8 @@
                 SUB_PROPERTY_NOT_INITIALIZED, mContext);
 
         // If it's never set, by default we return true.
-        return (setting == SUB_PROPERTY_NOT_INITIALIZED || setting == 1);
+        return (setting == SUB_PROPERTY_NOT_INITIALIZED
+                || setting == ImsConfig.FeatureValueConstants.ON);
     }
 
     /**
@@ -656,7 +660,7 @@
             return getBooleanCarrierConfig(
                     CarrierConfigManager.KEY_CARRIER_DEFAULT_WFC_IMS_ENABLED_BOOL);
         } else {
-            return setting == 1;
+            return setting == ImsConfig.FeatureValueConstants.ON;
         }
     }
 
@@ -936,7 +940,7 @@
             return getBooleanCarrierConfig(
                             CarrierConfigManager.KEY_CARRIER_DEFAULT_WFC_IMS_ROAMING_ENABLED_BOOL);
         } else {
-            return (setting == 1);
+            return setting == ImsConfig.FeatureValueConstants.ON;
         }
     }
 
@@ -1635,6 +1639,28 @@
         }
     }
 
+    public void setRttEnabled(boolean enabled) {
+        try {
+            setAdvanced4GMode(enabled || isEnhanced4gLteModeSettingEnabledByUser());
+            final int value = enabled ? ImsConfig.FeatureValueConstants.ON :
+                    ImsConfig.FeatureValueConstants.OFF;
+            Thread thread = new Thread(() -> {
+                try {
+                    Log.i(ImsManager.class.getSimpleName(), "Setting RTT enabled to " + enabled);
+                    getConfigInterface().setProvisionedValue(
+                            ImsConfig.ConfigConstants.RTT_SETTING_ENABLED, value);
+                } catch (ImsException e) {
+                    Log.e(ImsManager.class.getSimpleName(), "Unable to set RTT enabled to "
+                            + enabled + ": " + e);
+                }
+            });
+            thread.start();
+        } catch (ImsException e) {
+            Log.e(ImsManager.class.getSimpleName(), "Unable to set RTT enabled to " + enabled
+                    + ": " + e);
+        }
+    }
+
     /**
      * Set the TTY mode. This is the actual tty mode (varies depending on peripheral status)
      */
@@ -2061,7 +2087,9 @@
     public void factoryReset() {
         // Set VoLTE to default
         SubscriptionManager.setSubscriptionProperty(getSubId(),
-                SubscriptionManager.ENHANCED_4G_MODE_ENABLED, booleanToPropertyString(true));
+                SubscriptionManager.ENHANCED_4G_MODE_ENABLED,
+                booleanToPropertyString(getBooleanCarrierConfig(
+                        CarrierConfigManager.KEY_ENHANCED_4G_LTE_ON_BY_DEFAULT_BOOL)));
 
         // Set VoWiFi to default
         SubscriptionManager.setSubscriptionProperty(getSubId(),