Researched from Home Assistant, Companion app and Google documentation on October 25, 2026. This is an illustrative configuration walkthrough, not a test of a particular phone, car or smart-home device. Menu names vary with installed versions. The cover is an AI-generated editorial illustration.
Start with the native car controls
Home Assistant Android Auto works through the official Companion app. You do not need to send commands through Google Home just to use its on-screen controls. Home Assistant introduced this interface in its Android Auto announcement; the current car documentation describes setup and favorites.
Begin with one control that has an obvious result. An entity is a named control or reading inside Home Assistant. The practice entity below is only an on/off value in software. Once that works, use a script—a saved routine—to turn on selected entrance lights.
The order matters: first prove that the phone reaches your server, then prove that the car can send a command, and finally check the real lamp. A visible button or changing status alone does not prove that a tap reached its destination. Do all setup and troubleshooting while safely parked.
1. Check the phone, car and connection
- Confirm Android Auto compatibility. Google currently lists Android 11 or later, an active data plan and a compatible car or stereo. Wired use needs a suitable USB cable; wireless use also needs compatible wireless hardware. Check Google’s requirements for your exact combination.
- Install and sign in to Home Assistant on the phone. Use the official Play Store app, which supplies the full Android build. Follow the Companion setup instructions and confirm the correct server opens.
- Choose how the phone reaches home when away. Home Assistant Cloud remote access requires a paid subscription. A VPN, a private connection back to your home, is another option and must be connected when needed. The car interface does not supply that connection. See the official remote-access options and our remote-access setup guide.
Android Auto and Android Automotive are different. Android Auto uses your phone. Android Automotive OS runs apps in the vehicle itself. This walkthrough uses phone-based Android Auto. The current Companion docs note a favorites limitation for the app installed from Google Play directly on an Automotive vehicle; do not assume the phone’s favorite settings configure that separate installation.
2. Create the practice control
Using an administrator account, open Settings → Devices & services → Helpers → Create helper → Toggle. Name it Car practice. A helper stores a value without requiring hardware. Keep this new helper out of existing automations so changing it has no household effect. The Toggle helper reference explains its behavior.
Open its control in a second browser window and leave it off. On your phone, turn Car practice on and confirm the browser shows on. Turn it off again using the helper’s control in the browser. That gives you a known starting state for each test; no door, appliance or safety system needs to move.
3. Add a small favorites list
On the phone, open Settings → Companion app → Android Auto favorites, also called Driving favorites in some versions. Select Car practice. Reopen Home Assistant on the car display to see the updated list.
With Home Assistant 2025.12 or newer, the entity’s more-info menu also offers Add to → automotive favorite. Do that on the phone whose favorites you want to change. Vehicle-imposed list limits can affect how many entries appear. These paths are documented under Favorites.
4. Run the three-stage check
This is a proposed diagnostic exercise, not a measured vehicle test. Use the same Car practice helper throughout. Start it off before each attempt and look for an actual change to on in the second browser window.
On a phone, scroll the table sideways.
| Test | What to do | What a pass establishes |
|---|---|---|
| Phone on home Wi-Fi | Turn Car practice on in the phone app. | The signed-in phone can change this helper on this server. |
| Phone on cellular data | Before connecting Android Auto, disconnect from home Wi-Fi. Keep your chosen remote connection active. Repeat the tap. | The remote path works under these conditions. If it fails here, fix it before investigating the car. |
| Parked car display | Connect Android Auto, open Home Assistant and tap Car practice once. | The car interface can send this particular command. It does not certify every vehicle function or physical device. |
Wireless Android Auto itself uses Wi-Fi, so do not switch the phone’s Wi-Fi off during that connection. Perform the cellular-only check first. For a later away-from-home check, park somewhere outside your home network’s range and confirm your remote connection is available.
If the car displays a change made on the phone but its own tap does nothing, record those as two separate observations. Reading state and issuing a command are different parts of the check. Repeatedly tapping a real garage-door control would make the result harder to interpret.
5. Make an “Entrance lights on” routine
After the practice control works, choose one or two nonessential lights already controllable in Home Assistant. Confirm they respond normally while someone can observe them. This example deliberately leaves door locks and garage doors alone.
- Open Settings → Automations & scenes → Scripts → Create script → Create new script.
- Under Sequence, add Turn on light. Target only the chosen light entities, rather than an entire area that may include other lamps.
- Save as Entrance lights on. Run it from the phone and observe both lights.
- Add the saved script to your car favorites. With the vehicle parked, run it there and observe the same result.
The script editor instructions cover creating and running the routine. If you prefer the YAML text editor, use this as the contents of one new script, replacing both example entity IDs with your actual lights. Do not paste it into the main configuration file.
Example script: Entrance lights on
alias: Entrance lights on
mode: single
sequence:
- action: light.turn_on
target:
entity_id:
- light.porch
- light.hall_lampUse Turn on, not Toggle, for this routine. A second completed request should leave the lights on rather than reverse the first request. The Light reference documents the actions. This script does not turn the lamps off later; retain their ordinary manual control or existing bedtime routine. It also does not prevent another automation changing them.
A short script may show off again immediately after it finishes. That is its running status, not the lamp’s status. Check the light itself and its entity. Our scenes versus scripts guide explains how to share a routine with other controls. For a shortcut outside the car, see Home Assistant phone widgets.
Troubleshoot the part that failed
| What you see | Next check | Useful expected result |
|---|---|---|
| Home Assistant is absent from the car launcher. | Open it on the phone, confirm sign-in, and confirm it is enabled in Android Auto’s app launcher settings. Check whether the phone has disabled the unused app. | If unused-app disabling was the cause, the app should reappear. Google specifically documents this behavior on Samsung phones. |
| The app opens, but your chosen control is absent. | Confirm the favorite on the connected phone and the selected Home Assistant server. Reopen the car app. | Car practice appears. If it does, compare the missing item’s entity type with the official supported list. |
| Commands fail on both cellular and the car. | Return to the phone’s remote URL or VPN connection. | Car practice changes from the phone over cellular before you retry the car. |
| The phone works, but a car tap fails. | Repeat with Car practice, confirm the same server, and note phone, app, Android Auto and car software versions. | You have a reproducible car-only symptom to report, without guessing that device pairing is broken. |
| Car practice works, but a real light does not. | Try the light directly on the phone, then run the script there and check its targets. | You can separate a light/integration problem from a wrong script target. The successful helper test alone cannot choose between them. |
Google’s missing-launcher-app guidance supports reopening a disabled app as an early check. Avoid deleting the Companion app’s data or re-pairing home devices as the first response to a car-interface problem.
Keep convenience separate from access permissions
A short favorites list makes controls easier to find; it does not limit the signed-in account to those devices. Home Assistant’s view visibility settings and server permission model address different layers. A non-admin account plus hidden controls does not establish room-only authorization. See what restricted Home Assistant access can and cannot do before sharing an account or permanent car login.
For everyday use, start with a few unmistakable names and keep setup work parked. When planning local routines and shared household controls, “Entrance lights on” tells another person more than “Arrival scene 2.”
Does this work without internet?
The Android Auto interface does not make a remote Home Assistant server available offline. Away from home, your chosen connection needs to work. The lamp’s own integration may also have a cloud dependency. Keeping local automations on the home server and reaching that server from a car are separate questions.
Will this show my whole dashboard?
The official car interface presents supported entities and favorites; it is not the phone’s full dashboard. Start with those built-in controls. Treat third-party dashboard apps as separate projects with their own compatibility and safety limits.