diff --git a/esphome/components/modem/modem_component.cpp b/esphome/components/modem/modem_component.cpp
index 3147f1b6df..e1616b4eec 100644
--- a/esphome/components/modem/modem_component.cpp
+++ b/esphome/components/modem/modem_component.cpp
@@ -120,6 +120,10 @@ void ModemComponent::setup() {
   }
 
   this->reset_();
+  // At boot time, if the modem power  is up, but the modem is not ready, it is probably still in cmux mode
+  if (this->enabled_ && this->get_power_status() && !this->modem_ready()) {
+    this->exit_cmux_();
+  }
 
   ESP_LOGV(TAG, "Setup finished");
 }
@@ -127,6 +131,7 @@ void ModemComponent::setup() {
 void ModemComponent::reset_() {
   // destroy previous dte/dce, and recreate them.
   // destroying them seems to be the only way to have a clear state after hang up, and be able to reconnect.
+  // if the modem was previously in cmux mode, this->exit_cmux_(), will be needed after.
 
   this->dte_.reset();
   this->dce.reset();
@@ -186,21 +191,6 @@ void ModemComponent::reset_() {
   } else {
     ESP_LOGI(TAG, "not set_flow_control, because 2-wire mode active.");
   }
-
-  if (this->enabled_ && this->get_power_status() && !this->modem_ready()) {
-    // if the esp has rebooted, but the modem not, it is still in cmux mode
-    // So we close cmux.
-    // The drawback is that if the modem is poweroff, those commands will take some time to execute.
-    Watchdog wdt(60);
-    this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_MODE);
-    this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_COMMAND);
-    this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_EXIT);
-    if (!this->modem_ready()) {
-      ESP_LOGE(TAG, "Modem still not ready after reset");
-    } else {
-      ESP_LOGD(TAG, "Modem exited previous CMUX session");
-    }
-  }
 }
 
 bool ModemComponent::prepare_sim_() {
@@ -379,23 +369,12 @@ void ModemComponent::loop() {
             ESP_LOGE(TAG, "modem not ready after hang up");
           }
           this->set_timeout("wait_lost_ip", 60000, [this]() {
-            this->dump_connect_params_();
-            this->status_set_error("No lost ip event received");
+            this->status_set_error("No lost ip event received. Forcing disconnect state");
 
             this->state_ = ModemComponentState::DISCONNECTED;
 
-            // This seems to be the only way to exit CMUX
             this->reset_();  // reset dce/dte
-            if (!(this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_MODE) &&
-                  this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_EXIT))) {
-              this->status_set_error("Unable to exit CMUX.");
-            }
-
-            if (!this->modem_ready()) {
-              ESP_LOGE(TAG, "modem not ready after reset");
-            }
-
-            ///////////////////////////
+            this->exit_cmux_();
           });
         }
         this->start_ = false;
@@ -406,14 +385,7 @@ void ModemComponent::loop() {
 
         // This seems to be the only way to exit CMUX
         this->reset_();  // reset dce/dte
-        if (!(this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_MODE) &&
-              this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_EXIT))) {
-          this->status_set_error("Unable to exit CMUX.");
-        }
-
-        if (!this->modem_ready()) {
-          ESP_LOGE(TAG, "modem not ready after reset");
-        }
+        this->exit_cmux_();
       }
 
       break;
@@ -455,6 +427,25 @@ void ModemComponent::disable() {
   }
 }
 
+void ModemComponent::exit_cmux_() {
+  // This must be called to gain command mode if:
+  //   - if the esp has rebooted, but the modem not, it is still in cmux mode
+  //   - after a dte/dce reset.
+  // If the modem was previously ready, this will *HANG* de dte, and the modem will be unreachable, with no chances to
+  // recover it.
+  // We need this because we are not able to do a simple esp_modem::modem_mode::COMMAND_MODE (this is probably a bug in
+  // esp_modem)
+  Watchdog wdt(60);
+  this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_MODE);
+  this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_COMMAND);
+  this->dce->set_mode(esp_modem::modem_mode::CMUX_MANUAL_EXIT);
+  if (!this->modem_ready()) {
+    ESP_LOGE(TAG, "Modem still not ready after reset");
+  } else {
+    ESP_LOGD(TAG, "Modem exited previous CMUX session");
+  }
+}
+
 bool ModemComponent::get_power_status() {
   if (!this->status_pin_) {
     ESP_LOGV(TAG, "No status pin, assuming the modem is ON");
diff --git a/esphome/components/modem/modem_component.h b/esphome/components/modem/modem_component.h
index 2e5a5f35b6..cb663736ad 100644
--- a/esphome/components/modem/modem_component.h
+++ b/esphome/components/modem/modem_component.h
@@ -78,6 +78,14 @@ class ModemComponent : public Component {
 
  protected:
   void reset_();  // (re)create dte and dce
+  bool prepare_sim_();
+  void send_init_at_();
+  void start_connect_();
+  void poweron_();
+  void poweroff_();
+  static void ip_event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data);
+  void dump_connect_params_();
+  void exit_cmux_();
   InternalGPIOPin *tx_pin_;
   InternalGPIOPin *rx_pin_;
   InternalGPIOPin *status_pin_{nullptr};
@@ -98,19 +106,12 @@ class ModemComponent : public Component {
   esp_modem_dte_config_t dte_config_;
   esp_modem_dce_config_t dce_config_;
   ModemComponentState state_{ModemComponentState::DISABLED};
-  bool prepare_sim_();
-  void send_init_at_();
-  void start_connect_();
-  void poweron_();
-  void poweroff_();
   bool start_{false};
   bool enabled_{false};
   bool connected_{false};
   bool got_ipv4_address_{false};
   // date start (millis())
   uint32_t connect_begin_;
-  static void ip_event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data);
-  void dump_connect_params_();
   std::string use_address_;
   // timeout for AT commands
   uint32_t command_delay_ = 500;