diff --git a/core/java/android/hardware/face/FaceManager.java b/core/java/android/hardware/face/FaceManager.java
index 385ad2d3577fe..9e4234d558702 100644
--- a/core/java/android/hardware/face/FaceManager.java
+++ b/core/java/android/hardware/face/FaceManager.java
@@ -794,9 +794,9 @@ public class FaceManager implements BiometricAuthenticator, BiometricFaceConstan
         // This is used as a last resort in case a vendor string is missing
         // It should not happen for anything other than FACE_ERROR_VENDOR, but
         // warn and use the default if all else fails.
-        // TODO(b/196639965): update string
         Slog.w(TAG, "Invalid error message: " + errMsg + ", " + vendorCode);
-        return "";
+        return context.getString(
+                com.android.internal.R.string.face_error_vendor_unknown);
     }
 
     /**
diff --git a/core/java/android/hardware/fingerprint/FingerprintManager.java b/core/java/android/hardware/fingerprint/FingerprintManager.java
index 87d45b9de745b..6b2106a54b448 100644
--- a/core/java/android/hardware/fingerprint/FingerprintManager.java
+++ b/core/java/android/hardware/fingerprint/FingerprintManager.java
@@ -1390,9 +1390,9 @@ public class FingerprintManager implements BiometricAuthenticator, BiometricFing
         // This is used as a last resort in case a vendor string is missing
         // It should not happen for anything other than FINGERPRINT_ERROR_VENDOR, but
         // warn and use the default if all else fails.
-        // TODO(b/196639965): update string
         Slog.w(TAG, "Invalid error message: " + errMsg + ", " + vendorCode);
-        return "";
+        return context.getString(
+                com.android.internal.R.string.fingerprint_error_vendor_unknown);
     }
 
     /**
diff --git a/core/res/res/values/strings.xml b/core/res/res/values/strings.xml
index a99a22009e3bb..b58638cc3aded 100644
--- a/core/res/res/values/strings.xml
+++ b/core/res/res/values/strings.xml
@@ -1650,6 +1650,8 @@
     <!-- Array containing custom error messages from vendor.  Vendor is expected to add and translate these strings -->
     <string-array name="fingerprint_error_vendor">
     </string-array>
+    <!-- Default error message to use when fingerprint_error_vendor does not contain a message. [CHAR LIMIT=NONE] -->
+    <string name="fingerprint_error_vendor_unknown">Something went wrong. Try again.</string>
 
     <!-- Content description which should be used for the fingerprint icon. -->
     <string name="fingerprint_icon_content_description">Fingerprint icon</string>
@@ -1760,6 +1762,8 @@
     <!-- Array containing custom error messages from vendor.  Vendor is expected to add and translate these strings -->
     <string-array name="face_error_vendor">
     </string-array>
+    <!-- Default error message to use when face_error_vendor does not contain a message. [CHAR LIMIT=NONE] -->
+    <string name="face_error_vendor_unknown">Something went wrong. Try again.</string>
 
     <!-- Content description which should be used for the face icon. [CHAR LIMIT=10] -->
     <string name="face_icon_content_description">Face icon</string>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index 6802ae551e824..7799b8eb2fb20 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -2525,6 +2525,7 @@
   <java-symbol type="string" name="fingerprint_error_no_space" />
   <java-symbol type="string" name="fingerprint_error_timeout" />
   <java-symbol type="array" name="fingerprint_error_vendor" />
+  <java-symbol type="string" name="fingerprint_error_vendor_unknown" />
   <java-symbol type="string" name="fingerprint_acquired_partial" />
   <java-symbol type="string" name="fingerprint_acquired_insufficient" />
   <java-symbol type="string" name="fingerprint_acquired_imager_dirty" />
@@ -2564,6 +2565,7 @@
   <java-symbol type="string" name="face_error_no_space" />
   <java-symbol type="string" name="face_error_timeout" />
   <java-symbol type="array" name="face_error_vendor" />
+  <java-symbol type="string" name="face_error_vendor_unknown" />
   <java-symbol type="string" name="face_error_canceled" />
   <java-symbol type="string" name="face_error_user_canceled" />
   <java-symbol type="string" name="face_error_lockout" />