Easy Fixes for ‘Error 21’

Figuring out how to use a VPN with Android Auto can be frustrating, especially when the dreaded “Communication error 21” stops you in your tracks. If you’ve ever had to disconnect your VPN just to get it working in your car, you’re not alone.

Unlike regular apps, Android Auto acts as an extension of your phone, pulling data through predefined system functions instead of making direct network requests. Tech-speak aside, this setup doesn’t play nice with VPNs, which is why you run into that pesky red screen.

This guide covers why Android Auto doesn’t work with a VPN by default and how to bypass this limitation. Whether you prefer wired or wireless setups, you’ll find a few fixes to keep your VPN running without interruptions.

Why does Android Auto not work with a VPN?

Nothing like getting ready for a trip and having to pull out your phone to disconnect your VPN after running into this error (again):

“Android Auto encountered an error. Communication error 21 – Being connected to a VPN may prevent Android Auto from starting. If you’re using a VPN, turn it off and try reconnecting to Android Auto.”

Why does this happen even with the best Android VPNs? Surely, someone, whether Google or your VPN provider, must have figured out a fix by now?

It’s because Android Auto is an extension of your phone rather than a standalone system. When you connect to your car’s head unit, Android Auto routes data through your phone, but how it handles network requests differs from regular apps.

Here’s why Android Auto does not work with VPN directly:

• Direct network access restrictions: Android Auto uses predefined APIs to fetch data (see Android for Cars overview for details). Since apps running on Android Auto don’t make their own network calls, they generally don’t send their traffic via a VPN tunnel.
• Simplified functionality on Android Auto: Since AA is designed to be streamlined and user-friendly for driving, VPN compatibility may be intentionally left out. This keeps the focus on essential in-car functions (e.g., navigation, media playback).

It’s unlikely Google will add VPN functionality to the app in the future, considering they haven’t even done so for their Google Fi VPN and Google One VPN apps. Luckily, there are two ways to use a VPN with Android Auto and not get hit with error 21. Read on for the details.

How to use a VPN with Android Auto: 2 methods that work

One option is to plug your phone into the car with a cable. With a USB link, you can use a VPN with Android Auto and cruise past the usual roadblocks, as your phone and car can talk directly. No VPN rerouting issues, no “Communication error 21.”

What if you prefer to keep things wireless? Well, you can activate split tunneling via VPN settings instead. This excludes Android Auto from the VPN tunnel, allowing it to work correctly. Here’s how to do so, using NordVPN as an example:

1. Launch the VPN, tap your profile icon, and scroll to Settings.
2. Select Split tunneling and toggle on Use split tunneling.
3. In NordVPN, you can tick the Automatically exclude apps not compatible with VPN box to keep Android Auto traffic outside the VPN tunnel.
4. If your VPN does not have such a setting, tap Manage apps (it might be “Do not allow selected apps to use the VPN” or a similar phrase).
5. Find Android Auto in your list of installed apps, and tap the + sign next to it.
6. Reconnect to the VPN to save your changes (if needed), and that’s it!

This will add a split tunneling rule for Android Auto, so you won’t have to turn off your VPN whenever you connect to your car.

Android Auto still not working with a VPN? Try these fixes

Have you turned on split tunneling but Android Auto still won’t work with your VPN? Or worse, can’t find Android Auto in your VPN’s list of installed apps? Here’s what to do:

1. Check your kill switch settings

Your VPN kill switch may be interfering with your split tunneling settings. That’s because Android kill switches are usually designed to block all traffic if the VPN connection drops.

This can cause problems, as it might block Android Auto or other services that should bypass the VPN. While it can be a security issue (since your connection will be exposed if the VPN disconnects randomly), your only real option is to turn off the Android kill switch.

Here’s how to disable the kill switch in NordVPN. The process should be similar in other apps:

1. Open the VPN and access the app Settings.
2. Tap Kill switch then Open Android settings.
3. You’ll be taken to a list of existing VPN connections.
4. Tap the gear icon next to your VPN’s name to access the kill switch settings.
5. Toggle off Block connections without VPN.

How to use a VPN with Android Auto without disabling the kill switch

Some VPNs (such as Surfshark) offer a separate “VPN Kill Switch” option as a workaround, alongside the usual Android native Kill Switch. This should let you use Android Auto while the Surfshark Bypasser (split tunneling) is active. Here it is in action.

2. Set your VPN to show system apps

Some VPNs may hide system apps by default. As such, you might not be able to see Android Auto in the list of apps when trying to add a split tunneling rule. Look for three dots or buttons in the split tunneling menu that offer the option to Show system apps.

3. Configure Android to show system apps

Some users report not being able to see Android Auto when trying to add it as an exception for Google Fi’s built-in VPN. Here’s one suggested workaround:

1. Access your Android Settings.
2. Scroll down and tap on Apps.
3. Press the filter icon next to “Your apps.”
4. Toggle on Show system apps.

4. Manually install the Android Auto app

Another user reported manually installing Android Auto on their OnePlus 9 Pro device, allowing them to whitelist the app through the Google One VPN. If nothing else seems to work, this method is also worth a try.

VPN with Android Auto FAQs

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