How to tell Siri to pipe phone calls through your car speakers

By default, using "Hey Siri" to make a phone call uses the phone's speaker. But you can change that to use your car's speakers if your phone is plugged into your car's audio jack.

Lance Whitney Contributing Writer
Lance Whitney is a freelance technology writer and trainer and a former IT professional. He's written for Time, CNET, PCMag, and several other publications. He's the author of two tech books--one on Windows and another on LinkedIn.
Lance Whitney
3 min read

You can force Siri to pipe calls through your car speakers. Screenshot by Lance Whitney/CNET

I often use Siri in the car to make phone calls by uttering "Hey Siri" and telling it whom to call. But a tweak in iOS 8.3 and continued in just-released iOS 8.4 automatically pipes the call through my iPhone's speaker -- even if my phone is plugged into my car's audio jack. What if I want the call piped through my car's speakers instead?

Siri can be equally helpful and unhelpful, not always knowing what you want. It's machine technology after all, so it makes mistakes, especially if Apple updates the software with a new feature that doesn't work the way you want it to. Facing competition from Google Now, which is available on iOS, and Microsoft's Cortana, which will be available on iOS later this year, Apple keeps improving Siri. But certain "improvements" can actually make the software more difficult to use. And the insistence on using the phone's speaker when you tell Siri to make a call is one example.

Here's how it all works:

In iOS 8, Apple introduced the ability to activate Siri by voice. Saying "Hey Siri" turns on the voice assistant, which is then ready for your question or command. Your iPhone needs to be plugged into a power source for "Hey Siri" to work. "Hey Siri" is a great feature for me in my car as it allows me to make hands-free phone calls. My car has an audio jack, so I simply plug an audio cable from my iPhone to my car. And I plug my phone's power cable into one of my car's power outlets. Now I'm ready to make a phone call.

I say "Hey Siri" and tell it the name or number to dial. But by default, Siri puts the call on the iPhone's speaker courtesy of the iOS 8.3 update. (I tested it with iOS 8.4, which was released on Tuesday, and the audio setup requires the same workaround.)

No, Siri, that's not what I want. I want the phone call to go through my car's speakers. If you're stuck in this same situation, here's the fix:

  • Open Settings.
  • Tap the General screen.
  • In the General screen, tap Accessibility.
  • In the Accessibility screen, scroll down to the setting that says: "Call Audio Routing." You'll probably find that it's set to Automatic.
  • Tap the setting and change it to Headset. Tap the back button at the top to confirm that Call Audio Routing is now set to Headset.
  • The next time you tell Siri to make a phone call from your car, and your setup matches mine, the audio should pipe itself through your car speakers rather than through your iPhone's speaker. Siri will still tell you that it's making the call through the phone's speaker. But it will actually get directed to the phone's audio port and therefore to your car speakers.

Those of you who connect your iPhone to your car using Bluetooth may run into different results. But this worked for me.

Keep in mind that the workaround is only necessary if your phone is plugged into your car's power source and you use "Hey Siri" to tell it to make a phone call. Otherwise, the setting can be left alone. On a related note, the only major drawback is that if you want Siri to reverse course and to once again pipe a phone call through your iPhone's speaker under these same circumstances, you would have to change the setting back to Automatic.