diff --git a/cores/esp32/HardwareSerial.cpp b/cores/esp32/HardwareSerial.cpp
index a6a7573f6e3..7b13e3b9d30 100644
--- a/cores/esp32/HardwareSerial.cpp
+++ b/cores/esp32/HardwareSerial.cpp
@@ -340,14 +340,24 @@ void HardwareSerial::begin(unsigned long baud, uint32_t config, int8_t rxPin, in
 #if SOC_UART_HP_NUM > 2  // may save some flash bytes...
       case UART_NUM_2:
         if (rxPin < 0 && txPin < 0) {
+#ifdef RX2
           // do not change RX2/TX2 if it has already been set before
           rxPin = _rxPin < 0 ? (int8_t)RX2 : _rxPin;
+#endif
+#ifdef TX2
           txPin = _txPin < 0 ? (int8_t)TX2 : _txPin;
+#endif
         }
         break;
 #endif
     }
   }
+  // if no RX/TX pins are defined, it will not start the UART driver
+  if (rxPin < 0 && txPin < 0) {
+    log_e("No RX/TX pins defined. Please set RX/TX pins.");
+    HSERIAL_MUTEX_UNLOCK();
+    return;
+  }
 
   // IDF UART driver keeps Pin setting on restarting. Negative Pin number will keep it unmodified.
   // it will detach previous UART attached pins
diff --git a/cores/esp32/HardwareSerial.h b/cores/esp32/HardwareSerial.h
index 8eb7f2c91a6..a33d5def34d 100644
--- a/cores/esp32/HardwareSerial.h
+++ b/cores/esp32/HardwareSerial.h
@@ -200,8 +200,6 @@ typedef enum {
 #define RX2 (gpio_num_t)4
 #elif CONFIG_IDF_TARGET_ESP32S3
 #define RX2 (gpio_num_t)19
-#elif CONFIG_IDF_TARGET_ESP32P4
-#define RX2 (gpio_num_t)15
 #endif
 #endif
 
@@ -210,8 +208,6 @@ typedef enum {
 #define TX2 (gpio_num_t)25
 #elif CONFIG_IDF_TARGET_ESP32S3
 #define TX2 (gpio_num_t)20
-#elif CONFIG_IDF_TARGET_ESP32P4
-#define TX2 (gpio_num_t)14
 #endif
 #endif
 #endif /* SOC_UART_HP_NUM > 2 */
diff --git a/cores/esp32/esp32-hal-uart.c b/cores/esp32/esp32-hal-uart.c
index 706124c7451..7b2250c34fa 100644
--- a/cores/esp32/esp32-hal-uart.c
+++ b/cores/esp32/esp32-hal-uart.c
@@ -166,6 +166,7 @@ static bool _uartDetachBus_RX(void *busptr) {
   // sanity check - it should never happen
   assert(busptr && "_uartDetachBus_RX bus NULL pointer.");
   uart_t *bus = (uart_t *)busptr;
+  uart_set_loop_back(bus->num, false); // disable loopback
   return _uartDetachPins(bus->num, bus->_rxPin, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
 }
 
@@ -173,6 +174,7 @@ static bool _uartDetachBus_TX(void *busptr) {
   // sanity check - it should never happen
   assert(busptr && "_uartDetachBus_TX bus NULL pointer.");
   uart_t *bus = (uart_t *)busptr;
+  uart_set_loop_back(bus->num, false); // disable loopback
   return _uartDetachPins(bus->num, UART_PIN_NO_CHANGE, bus->_txPin, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
 }
 
@@ -1164,11 +1166,11 @@ unsigned long uartDetectBaudrate(uart_t *uart) {
    This function internally binds defined UARTs TX signal with defined RX pin of any UART (same or different).
    This creates a loop that lets us receive anything we send on the UART without external wires.
 */
-void uart_internal_loopback(uint8_t uartNum, int8_t rxPin) {
-  if (uartNum > SOC_UART_HP_NUM - 1 || !GPIO_IS_VALID_GPIO(rxPin)) {
+void uart_internal_loopback(uint8_t uartNum, bool loop_back_en) {
+  if (uartNum > SOC_UART_HP_NUM - 1) {
     return;
   }
-  esp_rom_gpio_connect_out_signal(rxPin, UART_TX_SIGNAL(uartNum), false, false);
+  uart_set_loop_back(uartNum, loop_back_en);
 }
 
 /*
diff --git a/cores/esp32/esp32-hal-uart.h b/cores/esp32/esp32-hal-uart.h
index 402b5785915..389193df9da 100644
--- a/cores/esp32/esp32-hal-uart.h
+++ b/cores/esp32/esp32-hal-uart.h
@@ -106,7 +106,7 @@ unsigned long uartDetectBaudrate(uart_t *uart);
 
 // Make sure UART's RX signal is connected to TX pin
 // This creates a loop that lets us receive anything we send on the UART
-void uart_internal_loopback(uint8_t uartNum, int8_t rxPin);
+void uart_internal_loopback(uint8_t uartNum, bool loop_back_en);
 
 // Routines that generate BREAK in the UART for testing purpose