The 15 inch MacBook Air M3 has Bluetooth 5.3 and the same Bluetooth stack as other Macs, and Apple's pages divide the faults into accessories that will not connect, accessories that connect and drop, and headsets that work for audio but not for the microphone. First make sure Bluetooth is on in System Settings, Bluetooth, using the trackpad if the keyboard is the problem. For Apple's Magic Keyboard, Magic Mouse or Magic Trackpad, Apple's page says to check the accessory is on and charged, connect it by cable to pair it, then disconnect. Remove and pair again if it was paired.
The checks in more detail
For a headset, open System Settings, Sound and pick the headset for both Output and Input, because a Mac may play through the headset but use the built-in microphone. The Air's Wi-Fi 6E and Bluetooth share an antenna area, and a busy 2.4 GHz network can disturb Bluetooth; Apple has guidance on interference, and moving the router's clients to 5 or 6 GHz helps. USB-C hubs and docks with poor shielding can emit noise that disturbs Bluetooth near the Air's left port, so unplug the hub to test, and keep wireless dongles on the other side.
If a device connects and then drops after a few minutes, a weak battery in the accessory is the first suspect. Handoff between Apple devices can steer AirPods to another device, so check which device they connect to. Restart the Mac, update macOS, and if Bluetooth is grayed out, shut down, wait thirty seconds and start again. Apple silicon Macs have no separate Bluetooth module reset in the menu; a restart does it. If a particular accessory fails on all computers, the accessory is at fault.
If no Bluetooth device ever connects after the steps, Apple Support should look at the Mac. Keep in mind that the 15 inch Air's larger body makes it comfortable on a lap, but a Mac on a metal desk, a metal laptop stand or a thick folio can shield the antenna, and moving it onto a wooden surface or removing the cover sometimes improves a poor Bluetooth link. Test with the Mac on a table beside the accessory to see whether the environment is the cause before changing settings.
Differential
Likely causes of “Apple MacBook Air 15-inch Bluetooth is missing, will not pair or disconnects”, and how to tell them apart
- 1
An accessory flat or off
What separates it It does not appear
How to confirm Charge it and pair by cable
- 2
A headset not chosen for input
What separates it Others cannot hear you
How to confirm Choose it for Input and Output
- 3
A stale pairing
What separates it It shows but will not connect
How to confirm Remove and pair again
- 4
A hub or 2.4 GHz interference
What separates it Dropouts
How to confirm Unplug the hub and use 5 GHz Wi-Fi
- 5
Handoff steering AirPods
What separates it They connect to another device
How to confirm Choose the Mac in the menu
Before you touch a setting
Record this first — changing settings destroys the evidence
- The accessory and its battery
- Whether a hub is attached
- Whether the headset is selected for input and output
- The macOS version
Try in this order
0 of 6 completedCheck Bluetooth is on
ReversibleSystem Settings, Bluetooth.
Pair Magic accessories by cable
ReversibleThen unplug.
Choose Input and Output
ReversibleIn Sound.
Unplug hubs
ReversibleTo test interference.
Remove and pair again
ReversibleIn Bluetooth.
Shut down for thirty seconds
ReversibleThen start.
Model-specific
What is true of this model and not of its siblings
- Shared area
- Wi-Fi and Bluetooth sit near each other.
- Hubs
- They can emit noise.
Stop boundary
When this stops being a self-service repair
- !If Bluetooth is grayed out after a shutdown, contact Apple Support
- !If one accessory fails everywhere, contact its maker
- !Replace a poor hub
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why do my AirPods keep leaving my Mac?+
Handoff steers them to another device.
Does the M3 Air have Bluetooth 5.3?+
Yes.
Can a hub affect Bluetooth?+
A poor one can.
How do I reset Bluetooth?+
Restart; there is no separate reset.