diff --git a/src/com/android/phone/CarrierConfigLoader.java b/src/com/android/phone/CarrierConfigLoader.java
index 1d0138b..9582dd0 100644
--- a/src/com/android/phone/CarrierConfigLoader.java
+++ b/src/com/android/phone/CarrierConfigLoader.java
@@ -141,6 +141,8 @@
     private static final int EVENT_FETCH_CARRIER_TIMEOUT = 15;
     // SubscriptionInfoUpdater has finished updating the sub for the carrier config.
     private static final int EVENT_SUBSCRIPTION_INFO_UPDATED = 16;
+    // Multi-SIM config changed.
+    private static final int EVENT_MULTI_SIM_CONFIG_CHANGED = 17;
 
     private static final int BIND_TIMEOUT_MILLIS = 30000;
 
@@ -174,28 +176,21 @@
         public void handleMessage(Message msg) {
             final int phoneId = msg.arg1;
             logWithLocalLog("mHandler: " + msg.what + " phoneId: " + phoneId);
+            if (!SubscriptionManager.isValidPhoneId(phoneId)
+                    && msg.what != EVENT_MULTI_SIM_CONFIG_CHANGED) {
+                return;
+            }
             switch (msg.what) {
                 case EVENT_CLEAR_CONFIG:
                 {
-                    /* Ignore clear configuration request if device is being shutdown. */
-                    Phone phone = PhoneFactory.getPhone(phoneId);
-                    if (phone != null) {
-                        if (phone.isShuttingDown()) {
-                            break;
-                        }
-                    }
-
-                    mConfigFromDefaultApp[phoneId] = null;
-                    mConfigFromCarrierApp[phoneId] = null;
-                    mServiceConnection[phoneId] = null;
-                    broadcastConfigChangedIntent(phoneId, false);
+                    clearConfigForPhone(phoneId, true);
                     break;
                 }
 
                 case EVENT_SYSTEM_UNLOCKED:
                 {
-                    for (int i = 0; i < TelephonyManager.from(mContext)
-                            .getSupportedModemCount(); ++i) {
+                    for (int i = 0; i < TelephonyManager.from(mContext).getActiveModemCount();
+                            ++i) {
                         // When user unlock device, we should only try to send broadcast again if we
                         // have sent it before unlock. This will avoid we try to load carrier config
                         // when SIM is still loading when unlock happens.
@@ -212,8 +207,7 @@
                     // Only update if there are cached config removed to avoid updating config for
                     // unrelated packages.
                     if (clearCachedConfigForPackage(carrierPackageName)) {
-                        int numPhones = TelephonyManager.from(mContext)
-                                .getSupportedModemCount();
+                        int numPhones = TelephonyManager.from(mContext).getActiveModemCount();
                         for (int i = 0; i < numPhones; ++i) {
                             updateConfigForPhoneId(i);
                         }
@@ -496,6 +490,9 @@
                 case EVENT_SUBSCRIPTION_INFO_UPDATED:
                     broadcastConfigChangedIntent(phoneId);
                     break;
+                case EVENT_MULTI_SIM_CONFIG_CHANGED:
+                    onMultiSimConfigChanged();
+                    break;
             }
         }
     }
@@ -555,6 +552,23 @@
         }
     }
 
+    private void clearConfigForPhone(int phoneId, boolean sendBroadcast) {
+        /* Ignore clear configuration request if device is being shutdown. */
+        Phone phone = PhoneFactory.getPhone(phoneId);
+        if (phone != null) {
+            if (phone.isShuttingDown()) {
+                return;
+            }
+        }
+
+        mConfigFromDefaultApp[phoneId] = null;
+        mConfigFromCarrierApp[phoneId] = null;
+        mServiceConnection[phoneId] = null;
+        mHasSentConfigChange[phoneId] = false;
+
+        if (sendBroadcast) broadcastConfigChangedIntent(phoneId, false);
+    }
+
     private void notifySubscriptionInfoUpdater(int phoneId) {
         String configPackagename;
         PersistableBundle configToSend;
@@ -919,6 +933,13 @@
         mHandler.sendMessage(mHandler.obtainMessage(EVENT_DO_FETCH_DEFAULT, phoneId, -1));
     }
 
+    private void onMultiSimConfigChanged() {
+        for (int i = TelephonyManager.from(mContext).getActiveModemCount();
+                i < mConfigFromDefaultApp.length; i++) {
+            clearConfigForPhone(i, false);
+        }
+    }
+
     @Override
     public @NonNull PersistableBundle getConfigForSubId(int subId, String callingPackage) {
         if (!TelephonyPermissions.checkCallingOrSelfReadPhoneState(
diff --git a/src/com/android/services/telephony/RadioOnHelper.java b/src/com/android/services/telephony/RadioOnHelper.java
index 741a6c5..981dc96 100644
--- a/src/com/android/services/telephony/RadioOnHelper.java
+++ b/src/com/android/services/telephony/RadioOnHelper.java
@@ -49,13 +49,19 @@
     }
 
     private void setupListeners() {
-        if (mListeners != null) {
-            return;
+        if (mListeners == null) {
+            mListeners = new ArrayList<>(2);
         }
-        mListeners = new ArrayList<>(2);
-        for (int i = 0; i < TelephonyManager.getDefault().getSupportedModemCount(); i++) {
+        int activeModems = TelephonyManager.from(mContext).getActiveModemCount();
+        // Add new listeners if active modem count increased.
+        while (mListeners.size() < activeModems) {
             mListeners.add(new RadioOnStateListener());
         }
+        // Clean up listeners if active modem count decreased.
+        while (mListeners.size() > activeModems) {
+            mListeners.get(mListeners.size() - 1).cleanup();
+            mListeners.remove(mListeners.size() - 1);
+        }
     }
     /**
      * Starts the "turn on radio" sequence. This is the (single) external API of the
@@ -76,7 +82,7 @@
         mCallback = callback;
         mInProgressListeners.clear();
         mIsRadioOnCallingEnabled = false;
-        for (int i = 0; i < TelephonyManager.getDefault().getSupportedModemCount(); i++) {
+        for (int i = 0; i < TelephonyManager.from(mContext).getActiveModemCount(); i++) {
             Phone phone = PhoneFactory.getPhone(i);
             if (phone == null) {
                 continue;
diff --git a/src/com/android/services/telephony/RadioOnStateListener.java b/src/com/android/services/telephony/RadioOnStateListener.java
index 729f6a9..52bd9cf 100644
--- a/src/com/android/services/telephony/RadioOnStateListener.java
+++ b/src/com/android/services/telephony/RadioOnStateListener.java
@@ -231,7 +231,7 @@
      * Note we don't call this method simply after a successful call to placeCall(), since it's
      * still possible the call will disconnect very quickly with an OUT_OF_SERVICE error.
      */
-    private void cleanup() {
+    public void cleanup() {
         Log.d(this, "cleanup()");
 
         // This will send a failure call back if callback has yet to be invoked.  If the callback