diff --git a/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelector.java b/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelector.java
index 00753ee..db0c31b 100644
--- a/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelector.java
+++ b/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelector.java
@@ -53,6 +53,7 @@
 import static android.telephony.NetworkRegistrationInfo.REGISTRATION_STATE_ROAMING;
 import static android.telephony.PreciseDisconnectCause.EMERGENCY_PERM_FAILURE;
 import static android.telephony.PreciseDisconnectCause.EMERGENCY_TEMP_FAILURE;
+import static android.telephony.PreciseDisconnectCause.SERVICE_OPTION_NOT_AVAILABLE;
 
 import android.annotation.NonNull;
 import android.content.Context;
@@ -170,6 +171,7 @@
 
     private CancellationSignal mCancelSignal;
 
+    // Members for carrier configuration
     private @RadioAccessNetworkType int[] mImsRatsConfig;
     private @RadioAccessNetworkType int[] mCsRatsConfig;
     private @RadioAccessNetworkType int[] mImsRoamRatsConfig;
@@ -179,8 +181,6 @@
     private List<String> mCdmaPreferredNumbers;
     private boolean mPreferImsWhenCallsOnCs;
     private int mVoWifiRequiresCondition;
-    private boolean mIsMonitoringConnectivity;
-    private boolean mWiFiAvailable;
     private int mScanTimeout;
     private int mMaxCellularTimeout;
     private int mMaxNumOfVoWifiTries;
@@ -190,6 +190,11 @@
     private boolean mRequiresImsRegistration;
     private boolean mRequiresVoLteEnabled;
     private boolean mLtePreferredAfterNrFailure;
+
+    // Members for states
+    private boolean mIsMonitoringConnectivity;
+    private boolean mWiFiAvailable;
+    private boolean mWasCsfbAfterPsFailure;
     private boolean mTryCsWhenPsFails;
     private boolean mTryEpsFallback;
     private int mModemCount;
@@ -366,11 +371,21 @@
             // Dial CS for CSFB instead of scanning with CS preferred network list.
             logi("reselectDomain tryCs=" + accessNetworkTypeToString(mCsNetworkType));
             if (mCsNetworkType != UNKNOWN) {
+                mWasCsfbAfterPsFailure = true;
                 onWwanNetworkTypeSelected(mCsNetworkType);
                 return;
             }
         }
 
+        if (mWasCsfbAfterPsFailure) {
+            mWasCsfbAfterPsFailure = false;
+            if (cause == SERVICE_OPTION_NOT_AVAILABLE) {
+                // b/299875872, combined attach but EXTENDED_SERVICE_REQUEST failed.
+                // Try CS preferred scan instead of PS preferred scan.
+                mLastNetworkType = EUTRAN;
+            }
+        }
+
         if (mMaxCellularTimerExpired) {
             if (mLastTransportType == TRANSPORT_TYPE_WWAN
                     && maybeDialOverWlan()) {
diff --git a/tests/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelectorTest.java b/tests/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelectorTest.java
index 72ef568..8a66c19 100644
--- a/tests/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelectorTest.java
+++ b/tests/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelectorTest.java
@@ -52,6 +52,7 @@
 import static android.telephony.NetworkRegistrationInfo.DOMAIN_PS;
 import static android.telephony.NetworkRegistrationInfo.REGISTRATION_STATE_HOME;
 import static android.telephony.NetworkRegistrationInfo.REGISTRATION_STATE_UNKNOWN;
+import static android.telephony.PreciseDisconnectCause.SERVICE_OPTION_NOT_AVAILABLE;
 
 import static com.android.services.telephony.domainselection.EmergencyCallDomainSelector.MSG_MAX_CELLULAR_TIMEOUT;
 import static com.android.services.telephony.domainselection.EmergencyCallDomainSelector.MSG_NETWORK_SCAN_TIMEOUT;
@@ -429,6 +430,41 @@
     }
 
     @Test
+    public void testDefaultCombinedImsRegisteredSelectPsThenExtendedServiceRequestFails()
+            throws Exception {
+        createSelector(SLOT_0_SUB_ID);
+        unsolBarringInfoChanged(false);
+
+        EmergencyRegResult regResult = getEmergencyRegResult(EUTRAN, REGISTRATION_STATE_HOME,
+                NetworkRegistrationInfo.DOMAIN_CS | NetworkRegistrationInfo.DOMAIN_PS,
+                true, true, 0, 0, "", "");
+        SelectionAttributes attr = getSelectionAttributes(SLOT_0, SLOT_0_SUB_ID, regResult);
+        mDomainSelector.selectDomain(attr, mTransportSelectorCallback);
+        processAllMessages();
+
+        bindImsService();
+
+        verifyPsDialed();
+
+        mDomainSelector.reselectDomain(attr);
+        processAllMessages();
+
+        verifyCsDialed();
+
+        //Extended service request failed
+        SelectionAttributes.Builder builder =
+                new SelectionAttributes.Builder(SLOT_0, SLOT_0_SUB_ID, SELECTOR_TYPE_CALLING)
+                .setCsDisconnectCause(SERVICE_OPTION_NOT_AVAILABLE)
+                .setEmergency(true)
+                .setEmergencyRegResult(regResult);
+        attr = builder.build();
+        mDomainSelector.reselectDomain(attr);
+        processAllMessages();
+
+        verifyScanCsPreferred();
+    }
+
+    @Test
     public void testDefaultCombinedImsNotRegisteredSelectCs() throws Exception {
         createSelector(SLOT_0_SUB_ID);
         unsolBarringInfoChanged(false);