Bluetooth Issues - Ubuntu.Fan

Basic Checks


# Bluetooth service status
systemctl status bluetooth
 
# Bluetooth adapter information (hciconfig is deprecated; use bluetoothctl/btmgmt)
bluetoothctl show
bluetoothctl list   # List all adapters
 
# RF switch status
rfkill list bluetooth

If Bluetooth is disabled:


sudo rfkill unblock bluetooth
sudo systemctl restart bluetooth

Using bluetoothctl


sudo bluetoothctl

Common commands:


power on              # Turn on Bluetooth
agent on              # Enable agent
default-agent         # Set as default agent
scan on               # Scan for devices
devices               # List discovered devices
pair XX:XX:XX:XX:XX   # Pair
trust XX:XX:XX:XX:XX  # Trust device
connect XX:XX:XX:XX:XX # Connect
info XX:XX:XX:XX:XX   # View device info
remove XX:XX:XX:XX:XX # Remove device
quit                  # Exit

Common Issues

Cannot discover devices


# Confirm the Bluetooth adapter is powered on
bluetoothctl power on
 
# Rescan
sudo bluetoothctl
scan on

If devices are still not found, check the kernel log:


sudo dmesg | grep -i bluetooth
sudo dmesg | grep -i "hci\|btusb"

Pairing failure

Remove the previous pairing record and pair again:


sudo bluetoothctl
remove XX:XX:XX:XX:XX:XX
scan on
pair XX:XX:XX:XX:XX:XX

Some devices require entering a PIN code, typically 0000 or 1234
Clear the Bluetooth cache:


sudo rm -rf /var/lib/bluetooth/*
sudo systemctl restart bluetooth

Paired but cannot connect


# Trust the device first
sudo bluetoothctl
trust XX:XX:XX:XX:XX:XX
connect XX:XX:XX:XX:XX:XX

If you get “Failed to connect: org.bluez.Error.Failed”:


# Restart the Bluetooth stack
sudo systemctl restart bluetooth
sudo modprobe -r btusb && sudo modprobe btusb

Frequent disconnections after connecting


# View Bluetooth logs
journalctl -u bluetooth -f
 
# Disable Bluetooth power management
sudo nano /etc/bluetooth/main.conf

Add or modify in the [Policy] section:


[Policy]
AutoEnable=true
 
[General]
FastConnectable=true

Restart the service:


sudo systemctl restart bluetooth

Poor Bluetooth headset audio quality

Bluetooth headsets may be using the SCO/HSP protocol (call mode) instead of A2DP (high quality audio).


# Check the current audio protocol
wpctl status
 
# Switch to A2DP in PipeWire
# In GNOME Sound settings, select the output profile as "High Fidelity Playback (A2DP Sink)"

Bluetooth keyboard/mouse latency

hcitool is deprecated; connection parameters are now negotiated automatically by the kernel and BlueZ. To troubleshoot latency, first confirm the connection with bluetoothctl info XX:XX:XX:XX:XX:XX, then inspect/manage the adapter with btmgmt:


# View adapter info and current connections
btmgmt info
btmgmt con      # List current connections

Upgrading BlueZ

Ubuntu 26.04 comes with the BlueZ Bluetooth stack. Check the version:


bluetoothd --version

If you encounter compatibility issues, install a newer version (if available):


sudo apt update
sudo apt install --only-upgrade bluez

USB Bluetooth Adapters

If the built-in Bluetooth is problematic, you can use a USB Bluetooth adapter:


# Confirm detection
lsusb | grep -i bluetooth
 
# Load driver
sudo modprobe btusb
 
# If there are multiple adapters, list and choose which one to use
bluetoothctl list                    # List all adapters and their MACs
bluetoothctl select XX:XX:XX:XX:XX:XX # Select a specific adapter
bluetoothctl power on                 # Power on that adapter

Bluetooth Log Debugging


# Enable verbose logging
sudo nano /etc/systemd/system/bluetooth.service.d/override.conf


[Service]
ExecStart=
ExecStart=/usr/libexec/bluetooth/bluetoothd -d


sudo systemctl daemon-reload
sudo systemctl restart bluetooth
journalctl -u bluetooth -f