diff --git a/include/ModemManager-enums.h b/include/ModemManager-enums.h
index 73fb2b9e..a8942ee2 100644
--- a/include/ModemManager-enums.h
+++ b/include/ModemManager-enums.h
@@ -92,6 +92,7 @@ typedef enum { /*< underscore_name=mm_modem_lock >*/
 
 /**
  * MMModemState:
+ * @MM_MODEM_STATE_FAILED: The modem is unusable.
  * @MM_MODEM_STATE_UNKNOWN: State unknown or not reportable.
  * @MM_MODEM_STATE_INITIALIZING: The modem is currently being initialized.
  * @MM_MODEM_STATE_LOCKED: The modem needs to be unlocked.
@@ -108,6 +109,7 @@ typedef enum { /*< underscore_name=mm_modem_lock >*/
  * Enumeration of possible modem states.
  */
 typedef enum { /*< underscore_name=mm_modem_state >*/
+    MM_MODEM_STATE_FAILED        = -1,
     MM_MODEM_STATE_UNKNOWN       = 0,
     MM_MODEM_STATE_INITIALIZING  = 1,
     MM_MODEM_STATE_LOCKED        = 2,
diff --git a/introspection/org.freedesktop.ModemManager1.Modem.xml b/introspection/org.freedesktop.ModemManager1.Modem.xml
index 7ddd6d7a..1a6b4519 100644
--- a/introspection/org.freedesktop.ModemManager1.Modem.xml
+++ b/introspection/org.freedesktop.ModemManager1.Modem.xml
@@ -172,8 +172,8 @@
         The modem's state (see #org.freedesktop.ModemManager1.Modem:State) changed.
     -->
     <signal name="StateChanged">
-      <arg name="old"    type="u" />
-      <arg name="new"    type="u" />
+      <arg name="old"    type="i" />
+      <arg name="new"    type="i" />
       <arg name="reason" type="u" />
     </signal>
 
@@ -333,7 +333,7 @@
         <link linkend="MM-MODEM-STATE-UNKNOWN:CAPS"><constant>MM_MODEM_STATE_UNKNOWN</constant></link>
         will be reported.
     -->
-    <property name="State" type="u" access="read" />
+    <property name="State" type="i" access="read" />
 
     <!--
         AccessTechnologies:
diff --git a/src/mm-base-modem.c b/src/mm-base-modem.c
index c8e042e0..7ad2f259 100644
--- a/src/mm-base-modem.c
+++ b/src/mm-base-modem.c
@@ -565,22 +565,18 @@ initialize_ready (MMBaseModem *self,
 
     if (!mm_base_modem_initialize_finish (self, res, &error)) {
         /* Wrong state is returned when modem is found locked */
-        if (g_error_matches (error,
-                             MM_CORE_ERROR,
-                             MM_CORE_ERROR_WRONG_STATE)) {
+        if (g_error_matches (error, MM_CORE_ERROR, MM_CORE_ERROR_WRONG_STATE))
             mm_dbg ("Couldn't finish initialization in the current state: '%s'",
                     error->message);
-            mm_base_modem_set_valid (self, TRUE);
-        } else {
+        else
             mm_warn ("couldn't initialize the modem: '%s'", error->message);
-            mm_base_modem_set_valid (self, FALSE);
-        }
-
         g_error_free (error);
-        return;
-    }
+    } else
+        mm_dbg ("modem properly initialized");
 
-    mm_dbg ("modem properly initialized");
+    /* Even with initialization errors, we do set the state to valid, so
+     * that the modem gets exported and the failure notified to the user.
+     */
     mm_base_modem_set_valid (self, TRUE);
 }
 
diff --git a/src/mm-broadband-modem.c b/src/mm-broadband-modem.c
index c6f55dc7..7b7b162f 100644
--- a/src/mm-broadband-modem.c
+++ b/src/mm-broadband-modem.c
@@ -6070,7 +6070,8 @@ disable (MMBaseModem *self,
     /* Check state before launching modem disabling */
     switch (MM_BROADBAND_MODEM (self)->priv->modem_state) {
     case MM_MODEM_STATE_UNKNOWN:
-        /* We should never have a UNKNOWN->DISABLED transition requested by
+    case MM_MODEM_STATE_FAILED:
+        /* We should never have a UNKNOWN|FAILED->DISABLED transition requested by
          * the user. */
         g_assert_not_reached ();
         break;
@@ -6078,7 +6079,7 @@ disable (MMBaseModem *self,
     case MM_MODEM_STATE_INITIALIZING:
     case MM_MODEM_STATE_LOCKED:
     case MM_MODEM_STATE_DISABLED:
-        /* Just return success, don't relaunch enabling */
+        /* Just return success, don't relaunch disabling */
         g_simple_async_result_set_op_res_gboolean (result, TRUE);
         break;
 
@@ -6350,7 +6351,8 @@ enable (MMBaseModem *self,
     /* Check state before launching modem enabling */
     switch (MM_BROADBAND_MODEM (self)->priv->modem_state) {
     case MM_MODEM_STATE_UNKNOWN:
-        /* We should never have a UNKNOWN->ENABLED transition */
+    case MM_MODEM_STATE_FAILED:
+        /* We should never have a UNKNOWN|FAILED->ENABLED transition */
         g_assert_not_reached ();
         break;
 
@@ -6420,7 +6422,6 @@ typedef enum {
     INITIALIZE_STEP_PRIMARY_OPEN,
     INITIALIZE_STEP_SETUP_SIMPLE_STATUS,
     INITIALIZE_STEP_IFACE_MODEM,
-    INITIALIZE_STEP_ABORT_IF_LOCKED,
     INITIALIZE_STEP_IFACE_3GPP,
     INITIALIZE_STEP_IFACE_3GPP_USSD,
     INITIALIZE_STEP_IFACE_CDMA,
@@ -6440,7 +6441,6 @@ typedef struct {
     InitializeStep step;
     MMAtSerialPort *port;
     gboolean close_port;
-    gboolean abort_if_locked;
 } InitializeContext;
 
 static void initialize_step (InitializeContext *ctx);
@@ -6486,6 +6486,49 @@ initialize_finish (MMBaseModem *self,
     return TRUE;
 }
 
+static void
+iface_modem_initialize_ready (MMBroadbandModem *self,
+                              GAsyncResult *result,
+                              InitializeContext *ctx)
+{
+    GError *error = NULL;
+
+    /* If the modem interface fails to get initialized, we will move the modem
+     * to a FAILED state. Note that in this case we still export the interface. */
+    if (!mm_iface_modem_initialize_finish (MM_IFACE_MODEM (self), result, &error)) {
+        /* Report the new FAILED state */
+        mm_warn ("Modem couldn't be initialized: %s", error->message);
+        g_error_free (error);
+
+        mm_iface_modem_update_state (MM_IFACE_MODEM (self),
+                                     MM_MODEM_STATE_FAILED,
+                                     MM_MODEM_STATE_CHANGE_REASON_UNKNOWN);
+
+        /* Just jump to the last step */
+        ctx->step = INITIALIZE_STEP_LAST;
+        initialize_step (ctx);
+        return;
+    }
+
+    /* bind simple properties */
+    mm_iface_modem_bind_simple_status (MM_IFACE_MODEM (self),
+                                       self->priv->modem_simple_status);
+
+    /* If we find ourselves in a LOCKED state, we shouldn't keep on
+     * the initialization sequence. Instead, we will re-initialize once
+     * we are unlocked. */
+    if (ctx->self->priv->modem_state == MM_MODEM_STATE_LOCKED) {
+        /* Jump to the Simple interface */
+        ctx->step = INITIALIZE_STEP_IFACE_SIMPLE;
+        initialize_step (ctx);
+        return;
+    }
+
+    /* Go on to next step */
+    ctx->step++;
+    initialize_step (ctx);
+}
+
 #undef INTERFACE_INIT_READY_FN
 #define INTERFACE_INIT_READY_FN(NAME,TYPE,FATAL_ERRORS)                 \
     static void                                                         \
@@ -6495,24 +6538,31 @@ initialize_finish (MMBaseModem *self,
     {                                                                   \
         GError *error = NULL;                                           \
                                                                         \
-        if (!mm_##NAME##_initialize_finish (TYPE (self),                \
-                                            result,                     \
-                                            &error)) {                  \
+        if (!mm_##NAME##_initialize_finish (TYPE (self), result, &error)) { \
             if (FATAL_ERRORS) {                                         \
-                g_simple_async_result_take_error (G_SIMPLE_ASYNC_RESULT (ctx->result), error); \
-                initialize_context_complete_and_free (ctx);             \
+                mm_warn ("Couldn't initialize interface: '%s'",         \
+                         error->message);                               \
+                g_error_free (error);                                   \
+                                                                        \
+                /* Report the new FAILED state */                       \
+                mm_iface_modem_update_state (MM_IFACE_MODEM (self),     \
+                                             MM_MODEM_STATE_FAILED,     \
+                                             MM_MODEM_STATE_CHANGE_REASON_UNKNOWN); \
+                                                                        \
+                /* Just jump to the last step */                        \
+                ctx->step = INITIALIZE_STEP_LAST;                       \
+                initialize_step (ctx);                                  \
                 return;                                                 \
             }                                                           \
                                                                         \
             mm_dbg ("Couldn't initialize interface: '%s'",              \
                     error->message);                                    \
-            /* Just shutdown the interface */                           \
+            /* Just shutdown this interface */                          \
             mm_##NAME##_shutdown (TYPE (self));                         \
             g_error_free (error);                                       \
         } else {                                                        \
             /* bind simple properties */                                \
-            mm_##NAME##_bind_simple_status (TYPE (self),                \
-                                            self->priv->modem_simple_status); \
+            mm_##NAME##_bind_simple_status (TYPE (self), self->priv->modem_simple_status); \
         }                                                               \
                                                                         \
         /* Go on to next step */                                        \
@@ -6520,7 +6570,6 @@ initialize_finish (MMBaseModem *self,
         initialize_step (ctx);                                          \
     }
 
-INTERFACE_INIT_READY_FN (iface_modem,           MM_IFACE_MODEM,           TRUE)
 INTERFACE_INIT_READY_FN (iface_modem_3gpp,      MM_IFACE_MODEM_3GPP,      TRUE)
 INTERFACE_INIT_READY_FN (iface_modem_3gpp_ussd, MM_IFACE_MODEM_3GPP_USSD, FALSE)
 INTERFACE_INIT_READY_FN (iface_modem_cdma,      MM_IFACE_MODEM_CDMA,      TRUE)
@@ -6586,6 +6635,7 @@ initialize_step (InitializeContext *ctx)
         /* Fall down to next step */
         ctx->step++;
     }
+
     case INITIALIZE_STEP_SETUP_SIMPLE_STATUS:
         /* Simple status must be created before any interface initialization,
          * so that interfaces add and bind the properties they want to export.
@@ -6603,20 +6653,6 @@ initialize_step (InitializeContext *ctx)
                                    ctx);
         return;
 
-    case INITIALIZE_STEP_ABORT_IF_LOCKED:
-        /* If we find ourselves in a LOCKED state, we shouldn't keep on
-         * the initialization sequence. Instead, we will re-initialize once
-         * we are unlocked. */
-        if (ctx->self->priv->modem_state == MM_MODEM_STATE_LOCKED) {
-            /* Jump to the Simple interface */
-            ctx->abort_if_locked = TRUE;
-            ctx->step = INITIALIZE_STEP_IFACE_SIMPLE;
-            initialize_step (ctx);
-            return;
-        }
-        /* Fall down to next step */
-        ctx->step++;
-
     case INITIALIZE_STEP_IFACE_3GPP:
         if (mm_iface_modem_is_3gpp (MM_IFACE_MODEM (ctx->self))) {
             /* Initialize the 3GPP interface */
@@ -6691,23 +6727,43 @@ initialize_step (InitializeContext *ctx)
         ctx->step++;
 
     case INITIALIZE_STEP_LAST:
-        if (ctx->abort_if_locked) {
+        if (ctx->self->priv->modem_state == MM_MODEM_STATE_FAILED) {
+            /* Fatal SIM failure :-( */
+            g_simple_async_result_set_error (ctx->result,
+                                             MM_CORE_ERROR,
+                                             MM_CORE_ERROR_WRONG_STATE,
+                                             "Modem is unusable, "
+                                             "cannot fully initialize");
+            /* Ensure we only leave the Modem interface around */
+            mm_iface_modem_3gpp_shutdown (MM_IFACE_MODEM_3GPP (ctx->self));
+            mm_iface_modem_3gpp_ussd_shutdown (MM_IFACE_MODEM_3GPP_USSD (ctx->self));
+            mm_iface_modem_cdma_shutdown (MM_IFACE_MODEM_CDMA (ctx->self));
+            mm_iface_modem_location_shutdown (MM_IFACE_MODEM_LOCATION (ctx->self));
+            mm_iface_modem_messaging_shutdown (MM_IFACE_MODEM_MESSAGING (ctx->self));
+            mm_iface_modem_time_shutdown (MM_IFACE_MODEM_TIME (ctx->self));
+            mm_iface_modem_simple_shutdown (MM_IFACE_MODEM_SIMPLE (ctx->self));
+            initialize_context_complete_and_free (ctx);
+            return;
+        }
+
+        if (ctx->self->priv->modem_state == MM_MODEM_STATE_LOCKED) {
             /* We're locked :-/ */
             g_simple_async_result_set_error (ctx->result,
                                              MM_CORE_ERROR,
                                              MM_CORE_ERROR_WRONG_STATE,
                                              "Modem is currently locked, "
                                              "cannot fully initialize");
-        } else {
-            /* All initialized without errors!
-             * Set as disabled (a.k.a. initialized) */
-            mm_iface_modem_update_state (MM_IFACE_MODEM (ctx->self),
-                                         MM_MODEM_STATE_DISABLED,
-                                         MM_MODEM_STATE_CHANGE_REASON_UNKNOWN);
-
-            g_simple_async_result_set_op_res_gboolean (G_SIMPLE_ASYNC_RESULT (ctx->result), TRUE);
+            initialize_context_complete_and_free (ctx);
+            return;
         }
 
+        /* All initialized without errors!
+         * Set as disabled (a.k.a. initialized) */
+        mm_iface_modem_update_state (MM_IFACE_MODEM (ctx->self),
+                                     MM_MODEM_STATE_DISABLED,
+                                     MM_MODEM_STATE_CHANGE_REASON_UNKNOWN);
+
+        g_simple_async_result_set_op_res_gboolean (G_SIMPLE_ASYNC_RESULT (ctx->result), TRUE);
         initialize_context_complete_and_free (ctx);
         return;
     }
@@ -6727,6 +6783,15 @@ initialize (MMBaseModem *self,
 
     /* Check state before launching modem initialization */
     switch (MM_BROADBAND_MODEM (self)->priv->modem_state) {
+    case MM_MODEM_STATE_FAILED:
+        /* NOTE: this will only happen if we ever support hot-plugging SIMs */
+        g_simple_async_result_set_error (result,
+                                         MM_CORE_ERROR,
+                                         MM_CORE_ERROR_WRONG_STATE,
+                                         "Cannot initialize modem: "
+                                         "device is unusable");
+        break;
+
     case MM_MODEM_STATE_UNKNOWN:
     case MM_MODEM_STATE_LOCKED: {
         InitializeContext *ctx;
diff --git a/src/mm-iface-modem-3gpp.c b/src/mm-iface-modem-3gpp.c
index 109cdd57..a2bbf20d 100644
--- a/src/mm-iface-modem-3gpp.c
+++ b/src/mm-iface-modem-3gpp.c
@@ -188,8 +188,10 @@ handle_register_auth_ready (MMBaseModem *self,
                   NULL);
 
     switch (modem_state) {
+    case MM_MODEM_STATE_FAILED:
     case MM_MODEM_STATE_UNKNOWN:
-        /* We should never have a UNKNOWN->REGISTERED transition */
+    case MM_MODEM_STATE_LOCKED:
+        /* We should never have such request (interface wasn't exported yet) */
         g_assert_not_reached ();
         break;
 
@@ -199,13 +201,6 @@ handle_register_auth_ready (MMBaseModem *self,
                                                MM_CORE_ERROR_WRONG_STATE,
                                                "Cannot register modem: "
                                                "device not fully initialized yet");
-        handle_register_context_free (ctx);
-        return;
-
-    case MM_MODEM_STATE_LOCKED:
-        /* We should never have such request in LOCKED state
-         * (interface wasn't exported yet) */
-        g_assert_not_reached ();
         break;
 
     case MM_MODEM_STATE_ENABLED:
@@ -381,8 +376,10 @@ handle_scan_auth_ready (MMBaseModem *self,
                   NULL);
 
     switch (modem_state) {
+    case MM_MODEM_STATE_FAILED:
     case MM_MODEM_STATE_UNKNOWN:
-        /* We should never have such request in UNKNOWN state */
+    case MM_MODEM_STATE_LOCKED:
+        /* We should never have such request (interface wasn't exported yet) */
         g_assert_not_reached ();
         break;
 
@@ -392,13 +389,6 @@ handle_scan_auth_ready (MMBaseModem *self,
                                                MM_CORE_ERROR_WRONG_STATE,
                                                "Cannot scan networks: "
                                                "device not fully initialized yet");
-        handle_scan_context_free (ctx);
-        return;
-
-    case MM_MODEM_STATE_LOCKED:
-        /* We should never have such request in LOCKED state
-         * (interface wasn't exported yet) */
-        g_assert_not_reached ();
         break;
 
     case MM_MODEM_STATE_DISABLED:
diff --git a/src/mm-iface-modem-cdma.c b/src/mm-iface-modem-cdma.c
index 925a3499..57914df1 100644
--- a/src/mm-iface-modem-cdma.c
+++ b/src/mm-iface-modem-cdma.c
@@ -130,8 +130,10 @@ handle_activate_auth_ready (MMBaseModem *self,
                   NULL);
 
     switch (modem_state) {
+    case MM_MODEM_STATE_FAILED:
     case MM_MODEM_STATE_UNKNOWN:
-        /* We should never have such request in UNKNOWN state */
+    case MM_MODEM_STATE_LOCKED:
+        /* We should never have such request (interface wasn't exported yet) */
         g_assert_not_reached ();
         break;
 
@@ -144,12 +146,6 @@ handle_activate_auth_ready (MMBaseModem *self,
         handle_activate_context_free (ctx);
         return;
 
-    case MM_MODEM_STATE_LOCKED:
-        /* We should never have such request in LOCKED state
-         * (interface wasn't exported yet) */
-        g_assert_not_reached ();
-        break;
-
     case MM_MODEM_STATE_ENABLED:
     case MM_MODEM_STATE_SEARCHING:
     case MM_MODEM_STATE_REGISTERED:
@@ -280,8 +276,10 @@ handle_activate_manual_auth_ready (MMBaseModem *self,
                   NULL);
 
     switch (modem_state) {
+    case MM_MODEM_STATE_FAILED:
     case MM_MODEM_STATE_UNKNOWN:
-        /* We should never have such request in UNKNOWN state */
+    case MM_MODEM_STATE_LOCKED:
+        /* We should never have such request (interface wasn't exported yet) */
         g_assert_not_reached ();
         break;
 
@@ -294,12 +292,6 @@ handle_activate_manual_auth_ready (MMBaseModem *self,
         handle_activate_manual_context_free (ctx);
         return;
 
-    case MM_MODEM_STATE_LOCKED:
-        /* We should never have such request in LOCKED state
-         * (interface wasn't exported yet) */
-        g_assert_not_reached ();
-        break;
-
     case MM_MODEM_STATE_ENABLED:
     case MM_MODEM_STATE_SEARCHING:
     case MM_MODEM_STATE_REGISTERED:
diff --git a/src/mm-iface-modem.c b/src/mm-iface-modem.c
index 3852d94d..62eac35f 100644
--- a/src/mm-iface-modem.c
+++ b/src/mm-iface-modem.c
@@ -1286,31 +1286,18 @@ handle_reset_auth_ready (MMBaseModem *self,
                   MM_IFACE_MODEM_STATE, &modem_state,
                   NULL);
 
-    switch (modem_state) {
-    case MM_MODEM_STATE_UNKNOWN:
-    case MM_MODEM_STATE_INITIALIZING:
-    case MM_MODEM_STATE_LOCKED:
+    if (modem_state < MM_MODEM_STATE_DISABLED) {
         g_dbus_method_invocation_return_error (ctx->invocation,
                                                MM_CORE_ERROR,
                                                MM_CORE_ERROR_WRONG_STATE,
                                                "Cannot reset modem: not initialized/unlocked yet");
         handle_reset_context_free (ctx);
         return;
-
-    case MM_MODEM_STATE_DISABLED:
-    case MM_MODEM_STATE_DISABLING:
-    case MM_MODEM_STATE_ENABLING:
-    case MM_MODEM_STATE_ENABLED:
-    case MM_MODEM_STATE_SEARCHING:
-    case MM_MODEM_STATE_REGISTERED:
-    case MM_MODEM_STATE_DISCONNECTING:
-    case MM_MODEM_STATE_CONNECTING:
-    case MM_MODEM_STATE_CONNECTED:
-        MM_IFACE_MODEM_GET_INTERFACE (self)->reset (MM_IFACE_MODEM (self),
-                                                    (GAsyncReadyCallback)handle_reset_ready,
-                                                    ctx);
-        break;
     }
+
+    MM_IFACE_MODEM_GET_INTERFACE (self)->reset (MM_IFACE_MODEM (self),
+                                                (GAsyncReadyCallback)handle_reset_ready,
+                                                ctx);
 }
 
 static gboolean
@@ -1399,10 +1386,7 @@ handle_factory_reset_auth_ready (MMBaseModem *self,
                   MM_IFACE_MODEM_STATE, &modem_state,
                   NULL);
 
-    switch (modem_state) {
-    case MM_MODEM_STATE_UNKNOWN:
-    case MM_MODEM_STATE_INITIALIZING:
-    case MM_MODEM_STATE_LOCKED:
+    if (modem_state < MM_MODEM_STATE_DISABLED) {
         g_dbus_method_invocation_return_error (ctx->invocation,
                                                MM_CORE_ERROR,
                                                MM_CORE_ERROR_WRONG_STATE,
@@ -1410,22 +1394,12 @@ handle_factory_reset_auth_ready (MMBaseModem *self,
                                                "not initialized/unlocked yet");
         handle_factory_reset_context_free (ctx);
         return;
-
-    case MM_MODEM_STATE_DISABLED:
-    case MM_MODEM_STATE_DISABLING:
-    case MM_MODEM_STATE_ENABLING:
-    case MM_MODEM_STATE_ENABLED:
-    case MM_MODEM_STATE_SEARCHING:
-    case MM_MODEM_STATE_REGISTERED:
-    case MM_MODEM_STATE_DISCONNECTING:
-    case MM_MODEM_STATE_CONNECTING:
-    case MM_MODEM_STATE_CONNECTED:
-        MM_IFACE_MODEM_GET_INTERFACE (self)->factory_reset (MM_IFACE_MODEM (self),
-                                                            ctx->code,
-                                                            (GAsyncReadyCallback)handle_factory_reset_ready,
-                                                            ctx);
-        break;
     }
+
+    MM_IFACE_MODEM_GET_INTERFACE (self)->factory_reset (MM_IFACE_MODEM (self),
+                                                        ctx->code,
+                                                        (GAsyncReadyCallback)handle_factory_reset_ready,
+                                                        ctx);
 }
 
 static gboolean
@@ -1649,6 +1623,7 @@ handle_set_bands_auth_ready (MMBaseModem *self,
                              GAsyncResult *res,
                              HandleSetBandsContext *ctx)
 {
+    GArray *bands_array;
     MMModemState modem_state;
     GError *error = NULL;
 
@@ -1663,10 +1638,7 @@ handle_set_bands_auth_ready (MMBaseModem *self,
                   MM_IFACE_MODEM_STATE, &modem_state,
                   NULL);
 
-    switch (modem_state) {
-    case MM_MODEM_STATE_UNKNOWN:
-    case MM_MODEM_STATE_INITIALIZING:
-    case MM_MODEM_STATE_LOCKED:
+    if (modem_state < MM_MODEM_STATE_DISABLED) {
         g_dbus_method_invocation_return_error (ctx->invocation,
                                                MM_CORE_ERROR,
                                                MM_CORE_ERROR_WRONG_STATE,
@@ -1674,27 +1646,14 @@ handle_set_bands_auth_ready (MMBaseModem *self,
                                                "not initialized/unlocked yet");
         handle_set_bands_context_free (ctx);
         return;
-
-    case MM_MODEM_STATE_DISABLED:
-    case MM_MODEM_STATE_DISABLING:
-    case MM_MODEM_STATE_ENABLING:
-    case MM_MODEM_STATE_ENABLED:
-    case MM_MODEM_STATE_SEARCHING:
-    case MM_MODEM_STATE_REGISTERED:
-    case MM_MODEM_STATE_DISCONNECTING:
-    case MM_MODEM_STATE_CONNECTING:
-    case MM_MODEM_STATE_CONNECTED: {
-        GArray *bands_array;
-
-        bands_array = mm_common_bands_variant_to_garray (ctx->bands);
-        mm_iface_modem_set_bands (MM_IFACE_MODEM (self),
-                                  bands_array,
-                                  (GAsyncReadyCallback)handle_set_bands_ready,
-                                  ctx);
-        g_array_unref (bands_array);
-        break;
-      }
     }
+
+    bands_array = mm_common_bands_variant_to_garray (ctx->bands);
+    mm_iface_modem_set_bands (MM_IFACE_MODEM (self),
+                              bands_array,
+                              (GAsyncReadyCallback)handle_set_bands_ready,
+                              ctx);
+    g_array_unref (bands_array);
 }
 
 static gboolean
@@ -1919,10 +1878,7 @@ handle_set_allowed_modes_auth_ready (MMBaseModem *self,
                   MM_IFACE_MODEM_STATE, &modem_state,
                   NULL);
 
-    switch (modem_state) {
-    case MM_MODEM_STATE_UNKNOWN:
-    case MM_MODEM_STATE_INITIALIZING:
-    case MM_MODEM_STATE_LOCKED:
+    if (modem_state < MM_MODEM_STATE_DISABLED) {
         g_dbus_method_invocation_return_error (ctx->invocation,
                                                MM_CORE_ERROR,
                                                MM_CORE_ERROR_WRONG_STATE,
@@ -1930,23 +1886,13 @@ handle_set_allowed_modes_auth_ready (MMBaseModem *self,
                                                "not initialized/unlocked yet");
         handle_set_allowed_modes_context_free (ctx);
         return;
-
-    case MM_MODEM_STATE_DISABLED:
-    case MM_MODEM_STATE_DISABLING:
-    case MM_MODEM_STATE_ENABLING:
-    case MM_MODEM_STATE_ENABLED:
-    case MM_MODEM_STATE_SEARCHING:
-    case MM_MODEM_STATE_REGISTERED:
-    case MM_MODEM_STATE_DISCONNECTING:
-    case MM_MODEM_STATE_CONNECTING:
-    case MM_MODEM_STATE_CONNECTED:
-        mm_iface_modem_set_allowed_modes (MM_IFACE_MODEM (self),
-                                          ctx->allowed,
-                                          ctx->preferred,
-                                          (GAsyncReadyCallback)handle_set_allowed_modes_ready,
-                                          ctx);
-        break;
     }
+
+    mm_iface_modem_set_allowed_modes (MM_IFACE_MODEM (self),
+                                      ctx->allowed,
+                                      ctx->preferred,
+                                      (GAsyncReadyCallback)handle_set_allowed_modes_ready,
+                                      ctx);
 }
 
 static gboolean
@@ -2075,9 +2021,8 @@ mm_iface_modem_unlock_check_finish (MMIfaceModem *self,
                                     GAsyncResult *res,
                                     GError **error)
 {
-    if (g_simple_async_result_propagate_error (G_SIMPLE_ASYNC_RESULT (res), error)) {
+    if (g_simple_async_result_propagate_error (G_SIMPLE_ASYNC_RESULT (res), error))
         return MM_MODEM_LOCK_UNKNOWN;
-    }
 
     return (MMModemLock) GPOINTER_TO_UINT (g_simple_async_result_get_op_res_gpointer (G_SIMPLE_ASYNC_RESULT (res)));
 }
@@ -2111,7 +2056,8 @@ unlock_check_ready (MMIfaceModem *self,
                                                                              &error);
     if (error) {
         /* Treat several SIM related, serial and other core errors as critical
-         * and abort the checks. */
+         * and abort the checks. These will end up moving the modem to a FAILED
+         * state. */
         if (error->domain == MM_SERIAL_ERROR ||
             g_error_matches (error,
                              MM_CORE_ERROR,
@@ -3014,6 +2960,7 @@ struct _InitializationContext {
     GSimpleAsyncResult *result;
     GCancellable *cancellable;
     MmGdbusModem *skeleton;
+    GError *fatal_error;
 };
 
 static InitializationContext *
@@ -3042,6 +2989,7 @@ initialization_context_new (MMIfaceModem *self,
 static void
 initialization_context_complete_and_free (InitializationContext *ctx)
 {
+    g_assert (ctx->fatal_error == NULL);
     g_simple_async_result_complete_in_idle (ctx->result);
     g_object_unref (ctx->cancellable);
     g_object_unref (ctx->self);
@@ -3116,22 +3064,23 @@ load_current_capabilities_ready (MMIfaceModem *self,
                                  GAsyncResult *res,
                                  InitializationContext *ctx)
 {
-    GError *error = NULL;
-
     /* We have the property in the interface bound to the property in the
      * skeleton. */
     g_object_set (self,
                   MM_IFACE_MODEM_CURRENT_CAPABILITIES,
-                  MM_IFACE_MODEM_GET_INTERFACE (self)->load_current_capabilities_finish (self, res, &error),
+                  MM_IFACE_MODEM_GET_INTERFACE (self)->load_current_capabilities_finish (self,
+                                                                                         res,
+                                                                                         &ctx->fatal_error),
                   NULL);
+    if (ctx->fatal_error) {
+        g_prefix_error (&ctx->fatal_error,
+                        "couldn't load Current Capabilities: ");
+        /* Jump to the last step */
+        ctx->step = INITIALIZATION_STEP_LAST;
+    } else
+        /* Go on to next step */
+        ctx->step++;
 
-    if (error) {
-        mm_warn ("couldn't load Current Capabilities: '%s'", error->message);
-        g_error_free (error);
-    }
-
-    /* Go on to next step */
-    ctx->step++;
     interface_initialization_step (ctx);
 }
 
@@ -3222,20 +3171,17 @@ load_unlock_required_ready (MMIfaceModem *self,
                             GAsyncResult *res,
                             InitializationContext *ctx)
 {
-    GError *error = NULL;
-
     /* NOTE: we already propagated the lock state, no need to do it again */
-    mm_iface_modem_unlock_check_finish (self, res, &error);
-    if (error) {
-        /* FATAL */
-        mm_warn ("couldn't load unlock required status: '%s'", error->message);
-        g_simple_async_result_take_error (ctx->result, error);
-        initialization_context_complete_and_free (ctx);
-        return;
-    }
+    mm_iface_modem_unlock_check_finish (self, res, &ctx->fatal_error);
+    if (ctx->fatal_error) {
+        g_prefix_error (&ctx->fatal_error,
+                        "Couldn't check unlock status: ");
+        /* Jump to the last step */
+        ctx->step = INITIALIZATION_STEP_LAST;
+    } else
+        /* Go on to next step */
+        ctx->step++;
 
-    /* Go on to next step */
-    ctx->step++;
     interface_initialization_step (ctx);
 }
 
@@ -3612,51 +3558,54 @@ interface_initialization_step (InitializationContext *ctx)
     }
 
     case INITIALIZATION_STEP_LAST:
-        /* We are done without errors! */
+        if (ctx->fatal_error) {
+            g_simple_async_result_take_error (ctx->result, ctx->fatal_error);
+            ctx->fatal_error = NULL;
+        } else {
+            /* We are done without errors!
+             * Handle method invocations */
+            g_signal_connect (ctx->skeleton,
+                              "handle-create-bearer",
+                              G_CALLBACK (handle_create_bearer),
+                              ctx->self);
+            g_signal_connect (ctx->skeleton,
+                              "handle-command",
+                              G_CALLBACK (handle_command),
+                              ctx->self);
+            g_signal_connect (ctx->skeleton,
+                              "handle-delete-bearer",
+                              G_CALLBACK (handle_delete_bearer),
+                              ctx->self);
+            g_signal_connect (ctx->skeleton,
+                              "handle-list-bearers",
+                              G_CALLBACK (handle_list_bearers),
+                              ctx->self);
+            g_signal_connect (ctx->skeleton,
+                              "handle-enable",
+                              G_CALLBACK (handle_enable),
+                              ctx->self);
+            g_signal_connect (ctx->skeleton,
+                              "handle-reset",
+                              G_CALLBACK (handle_reset),
+                              ctx->self);
+            g_signal_connect (ctx->skeleton,
+                              "handle-factory-reset",
+                              G_CALLBACK (handle_factory_reset),
+                              ctx->self);
+            g_signal_connect (ctx->skeleton,
+                              "handle-set-bands",
+                              G_CALLBACK (handle_set_bands),
+                              ctx->self);
+            g_signal_connect (ctx->skeleton,
+                              "handle-set-allowed-modes",
+                              G_CALLBACK (handle_set_allowed_modes),
+                              ctx->self);
+            g_simple_async_result_set_op_res_gboolean (ctx->result, TRUE);
+        }
 
-        /* Handle method invocations */
-        g_signal_connect (ctx->skeleton,
-                          "handle-create-bearer",
-                          G_CALLBACK (handle_create_bearer),
-                          ctx->self);
-        g_signal_connect (ctx->skeleton,
-                          "handle-command",
-                          G_CALLBACK (handle_command),
-                          ctx->self);
-        g_signal_connect (ctx->skeleton,
-                          "handle-delete-bearer",
-                          G_CALLBACK (handle_delete_bearer),
-                          ctx->self);
-        g_signal_connect (ctx->skeleton,
-                          "handle-list-bearers",
-                          G_CALLBACK (handle_list_bearers),
-                          ctx->self);
-        g_signal_connect (ctx->skeleton,
-                          "handle-enable",
-                          G_CALLBACK (handle_enable),
-                          ctx->self);
-        g_signal_connect (ctx->skeleton,
-                          "handle-reset",
-                          G_CALLBACK (handle_reset),
-                          ctx->self);
-        g_signal_connect (ctx->skeleton,
-                          "handle-factory-reset",
-                          G_CALLBACK (handle_factory_reset),
-                          ctx->self);
-        g_signal_connect (ctx->skeleton,
-                          "handle-set-bands",
-                          G_CALLBACK (handle_set_bands),
-                          ctx->self);
-        g_signal_connect (ctx->skeleton,
-                          "handle-set-allowed-modes",
-                          G_CALLBACK (handle_set_allowed_modes),
-                          ctx->self);
-
-        /* Finally, export the new interface */
+        /* Finally, export the new interface, even if we got errors */
         mm_gdbus_object_skeleton_set_modem (MM_GDBUS_OBJECT_SKELETON (ctx->self),
                                             MM_GDBUS_MODEM (ctx->skeleton));
-
-        g_simple_async_result_set_op_res_gboolean (ctx->result, TRUE);
         initialization_context_complete_and_free (ctx);
         return;
     }