When Sidecar fails with a “device timed out” error, terminating the SidecarRelay process on your iPad typically resolves the issue, which saves you rebooting your iPad.

Note

This is an advanced technique that requires using a terminal and that Xcode to be installed on your Mac.

Prerequisites

You’ll need the devicectl command, which requires Xcode is installed

Step 1: Find your device

devicectl list devices

This will output a list of connected devices. Note the device identifier (e.g., Stuart-Carnies-iPad-809.coredevice.local).

Step 2: Find the SidecarRelay process

Replace <DEVICE_ID> with your device identifier from Step 1:

devicectl device info processes --device <DEVICE_ID> | grep 'SidecarRelay'

This will show the SidecarRelay process. Note the process ID (PID) from the output (e.g., 709).

Step 3: Kill the process

Replace <PID> with the process ID from Step 2 and <DEVICE_ID> with your device identifier:

devicectl device process terminate --kill -p <PID> --device <DEVICE_ID>

After terminating the process, try reconnecting.