GoKawiilRemoving the Modem and GPS from my 2024 RAV4 Hybrid
Modern cars are computers on wheels - they have more sensors than you can count and are constantly phoning home with telemetry data like your location, speed, fuel levels, sudden accelerations/decelerations, video footage, driver attention data from eye monitoring systems, and hundreds of other data points. Cars have inward- and outward-facing cameras. They have microphones. They have always-on modems. It’s all enabled by default with difficult or meaningless opt-outs, and your data is monetized through brokers like LexisNexis or Verisk. This all brings a host of security and privacy issues - here are some over the years:
Now that we’re sufficiently motivated, what can we do about it? In this blog post, rather than relying on companies’ promises or meaningless opt-outs, we’re going to stop the data at the source by physically removing the modem (the DCM, or Data Communication Module) as well as the built-in GPS on my 2024 RAV4 Hybrid, so the car will no longer have the capability to send any telemetry data back home. Let’s dive in:
Will the car still be functional?
Yes. Depending on how different car manufacturers have wired their cars, how their software and firmware were written, etc., varying levels of functionality might be affected by removing the modem and GPS. For this car:
Everything that relies on a data connection will no longer work. This includes things like over-the-air updates as well as Toyota cloud-based services and SOS functionality This is a safety tradeoff - you’re disabling automatic crash notification and emergency calling
The car’s microphone is wired through the DCM, and in the absence of any other changes removing the DCM means the in-car microphone won’t work, which is inconvenient if you plan on taking calls in the car. However we’ll install a DCM Bypass Kit (discussed more below) to restore all functionality and have a working microphone
CarPlay has a quirk: the phone uses its own GPS but also accepts a location signal from the car’s GPS unit. After removing the DCM, the car would get confused about its location and sometimes jump my position to the middle of Nevada (I live in San Francisco), making navigation annoying. To work around this we’ll fully disconnect the car’s GPS, so it can’t send a bad location to the phone From the title of the blog post you might have wondered why bother removing the GPS after we’ve removed the modem - who cares if the car has built-in location when it can’t phone home with that data? This is why This is a well-documented bug with discussions on Apple Support threads as well as car-specific forums like rav4world. This bug affects more than just Toyotas, it’s a generic Apple bug even for people who haven’t removed their modem (but anecdotally removing my modem made the problem worse)
Removing the DCM and GPS may void parts of your warranty - just something to be aware of. Thanks to the Magnuson–Moss Warranty Act, it cannot void the whole car warranty. It can void coverage related to the work you did (cloud services, telematics, etc.) but unrelated failures like engine problems must still be covered
So thankfully everything in the car remains 100% functional except the cloud-based services mentioned above, which I didn’t want anyway. There is also one critical caveat about Bluetooth:
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