Honda Headunit Reverse Engineering, And The Dismal State Of Infotainment Systems

These days the dozen or so ECUs in an average car are joined by an infotainment system of some type, which are typically a large touch screen on the dashboard (the headunit) and possibly a couple of auxiliary units for the rear seats. These infotainment systems run anything from QNX to (Yocto) Linux or more commonly these days some version of Android. As [Eric McDonald] discovered with his 2021 Honda Civic, its headunit runs an archaic Android dating back to roughly 2012.

While this offers intriguing options with gaining root access via decade-old exploits that the car manufacturer never fixed, as [Eric] notes, this is an advantage that anyone who can gain access to the car’s CAN buses via e.g. the headlights, a wireless access point, or even inject an exploit via ADB radio can use to their advantage. Essentially, these infotainment systems are massive attack surfaces with all of their wired and wireless interfaces, combined with outdated software that you as the vehicle owner are forbidden to meddle with by the manufacturer.

Naturally taking this ‘no’ as a challenge as any civilized citizen would, [Eric] set out to not only root the glorified Android tablet that Honda seeks to pass off as a ‘modern infotainment system’, but also reverse-engineer the system as far as possible and documenting the findings on GitHub. As [Eric] also explains in a Hacker News discussion, his dream is to not only have documentation available for infotainment systems in general as a community effort, but also provide open source alternatives that can be inspected by security researchers rather than being expected to lean on the ‘trust me bro’ security practices of the average car manufacturer.

Although a big ask considering how secretive car manufacturers are, this would seem to be an issue that we should tackle sooner rather than later, as more and more older cars turn into driving security exploits just waiting to happen.

47 thoughts on “Honda Headunit Reverse Engineering, And The Dismal State Of Infotainment Systems

  1. First off, an “infotainment system” in a vehicle shouldn’t even exist !
    The principal task when operating a 2 ton piece of steel that can easily create havoc, should be “drive the damn thing !” PAY ATTENTION TO THE ROAD ! not playing with the freakin’ “head unit”.

    “distracted driving” indeed !

    There’s a reason the EICAS or EACAM (Airbus), filters out time irrelevant data from being presented to the pilots. It just distracts them from their primary task of situational awareness in flying the aircraft.

    It’s a pity drivers aren’t held to the same tough standards ATP’s are held to.

    1. I agree… Infotainment systems don’t belong in vehicles. Cell phones are bad enough (which if you think about could take the place of ‘infotain’ systems anyway. All that fancy stuff and they still can’t automatically keep the time on the console set to the current local time :) . At least on all of my vehicles I own.

      1. Look out! He’s (or she) invented Android Auto and carplay!

        As much as I would prefer the in-car systems be limited to *repeatable, tactile inputs*, rather than touchscreen junk… the cellphone problem isn’t going away. Maybe harsher penalties would help, but we still have plenty of DUIs, telling of human nature.

        We’re at the point where *supplementing* a driver’s attentiveness is a very valid goal for in-car systems.

        I can’t help but think that we’re also trending towards cars that are less-and-less engaging to *drive* – which probably further the distracted driving problem.

        1. Whenever the DUI money starts to slim down, they just redefine ‘drunk’ again.

          Actual drunk remains 0.15 BAC. Same as legal drunk started at. Before MADD turned into a cash cow.

          That said: I once saw an old lady doing needlepoint on her steering wheel as she drove down the interstate in California. Stitch, stitch, look at road…repeat.

      2. I can’t see much of anything behind me from within modern cars, so the rearview camera is appreciated. But most of the things they use the screen for while driving shouldn’t use the screen for inputs, just display. It’s the *touch* part that’s the problem in daytime. The light from the screen is only an issue in the dark.

    2. While I agree in principle aviation is a bad example- usually one pilot’s sole job is to keep head in cockpit and monitor systems, callouts etc and generally feed critical information to the pilot flying the plane. It is also a very highly regimented system.
      Also, as a gross generalization, airbus is on the side of “pilot” monitors the autopilot whereas Boeing is the opposite. Neither is superior and both have merits and downsides.
      I Absolutely agree about distracted driving etc but it simply isn’t practical to have one dude driving while another monitors systems unless you are a professional road rally racer. It is fun on a bros only road trip though.

    3. 100% agree. At least in my state we have made it illegal to use a cell phone while driving a car, a pretty sensible law in my opinion. As a cyclist who spends a lot of time on the road, it is terrifying to me to see the sheer number of people using phones while “driving”.

      Having what amounts to an Android tablet stuck in the middle of the car kind of defeats the point of driving- but unfortunately, it is getting harder (if not impossible) for vehicle manufacturers to sell cars that don’t have these kinds of devices in them.

      1. I’m guessing you’ve never seen s cyclist weaving and bobbing like a drunk guy, only to discover on closer approach that he was messing with his phone… I have. And it’s not just “the” time it happened, either.

        In fact, I saw at least one instance where a distracted pedestrian nearly bought the farm.

    4. I’ll take the opposite point of view. From what I gather, you would rather be the only occupant of a vehicle, no pedestrians, no street venders, no bicycles, no other automobiles/trucks sharing “your” road. Otherwise, all of those objects would be distractions and hinder your ability to operate your car safely.

      In my world there are literally thousands of distractions that can change in less than a moments notice. Situational and operational awareness are key. I’m not saying the center console should have a web browser operational during driving, but other forms of entertainment seem important to various degrees. Very little in our world seems absolute.

      Infotainment systems with music and/or audiobooks, voice guided GPS, vehicle status, and hands-free cell phone capability all seem to be, in my mind, contributors toward safety.

      As to aircraft, three pilots taking care of 300+ passengers going 600 miles an hour without geographical/topographic landmarks would seem to explain the reason why there are hundreds of indicators and switches and a plethora of potential alarms. I hope you’re not trying to tell me the control systems in a cockpit are far simpler than an automobile.

      1. Anything not related to driving is a distraction, passengers, phones, billboards.
        Everything else like the other cars, road signs, pedestrians, the street vendor are the obtacles you are SUPPOSED to be giving ALL of your very limited attention to.

        Your brain lies to you all day, every day.
        You cannot multi task.
        You cannot have a conversation with someone without being “present” in that conversation in your head. Which is NOT driving.
        You cannot listen to music, or worse a book, and drive. You are doing one or the other.

        Does that make driving “less fun”? I dunno. I enjoy operating a vehicle. If people have to distract themselves with music or a book then probably yes.
        Is that “too bad”? Also a resounding yes.

        You are privileged to be able to operate a muli-ton metal box at lethal speeds, for the simple convenience of not having to walk or take “public” transportation.

        About 40k people in the USA die every year from vehicles.
        At least SOME of those people would still be alive if those drivers hadn’t distracted themself from the “oh so boring chore” of driving.

        If you think it’s unreasonable to eliminate non-driving things while you are driving, then you shouldn’t BE driving.

      2. I agree more on your side. Sure music ect. Is in some cases distracting, but its also sometimes really helpful for occupying your mind just enough that you dont get more distracted. Its like listening to music while working with your hands, i find that part of my mind will find something to think about thats more distracting if I dont give it something to do and it doesnt really impact my visual and motor parts of my mind. Music should of corse be at a moderate volume and be familiar.

        Also gps with a good sized map is essential for safety. There is no more dangerous of a driver than one who is lost and doesnt know that the road has some crazy merge coming up or some other feature that will require action.

    5. Depending on the news page you prefer we lose between 8 and 11 people a day to distracted driving. Even if it were five a day, killing someone due to careless driving or an inability to ignore a text message should be treated as criminally negligent homicide.

      I was a volunteer firefighter in college and even back then, 2007 – 2010, we were seeing an uptick in accidents due to distracted drivers. “but I only looked down for a second…” Yeah well, that second cost you a functional leg and killed someone’s grand parent.

    6. “First off, an “infotainment system” in a vehicle shouldn’t even exist !” …Stryker mumbles as he drifts off to sleep behind the wheel of a very silent car after too many miles of monotonous road.

    7. I’m going to call you out here. Infotainment in my car is no different than a 1950s radio… its just a play button + indicator of what is playing and a next button. Are you suggesting that radios that have been in cards for 70-80+ years were a bad idea… that seems laughable.

      GPS maps with live updates on traffic are also super useful. I have a 10in unit in my 2000 Honda insight, and it makes it better to drive than my 2017 accord which only has a basic head unit and no GPS only bluetooth.

      As far as all the rest of the stuff it can do… its typically quite limited (even on Chinese units that skirt regulations). I do find text to speech and speech to text messaging dubious… its more of a distraction than a help IMO.

      1. I agree with your assessment. We dont have one in our old accord but man I would love to have a honkin GPS display. Like any tool, it is how a person uses it. I don’t really think the driver should be watching movies but we are always gonna have need for safety rails and do not eat prep H labels lol. I am curious to see how it goes when we do get a new car that will invariably have something like that. It is like CVT and turbo in some cases that are standard. I guess to each their own. I will be excited to navigate on something I can see though :)

      2. Yeah I was driving in Dallas recently and didn’t always have the luxury of a passenger to help me navigate. It was either glance over at the rather large route map with directions to try to figure out which freaking lane to be in to catch one of the 3 or 4 exits in the same quarter mile stretch or stare at my phone or stare at my little phone screen for a lot longer. Likewise being able to easily stream spotify or audiobooks is likely less a distraction than having to channel surf on long drives as I leave the range of the last radio station.

        Could the concept be make for a less safe driving experience absolutely but that doesn’t mean every usage does. Hell, looking out windows can be a distraction, should we build high walls for midwestern tourists along all the routes they’d take in Colorado where mountains are visible?

        1. Cars that have built in maps that aren’t updated turn into misinformation generators over time, of course. Personally, I find mounting a phone with a map app to the dash and not touching it to be equivalent to a tomtom. It’s not as easy to justify needing a lot of attention for the “tainment” part of infotainment. But for gps, the concept behind the phrase “aviate, navigate, communicate” applies. Navigation is still pretty high up the priority list, which is why it was worth it.

      3. Several studies show that listening to music, books, or even talking to passengers “removes you from the present”.

        Your brain is lying to you to make you think you can do more than one thing at a time.

        It’s an inconvenient truth when things we have been doing “for years” are actually a bad thing.
        It doesn’t make it okay to keep doing them.

        1. “Your brain is lying to you to make you think you can do more than one thing at a time.”
          I can prove that you don’t really believe that with a very simple question. Do you fall over if someone talks to you while you’re walking around a crowded restaurant? Because if walking in that situation is fully automatic for you, then you admit the brain can do things in the background, and if it isn’t then it’s a continuous conscious process of looking around and avoiding tables and chairs and people. People can’t hold every sound they’ve heard in their short term memory indefinitely – by the time you make it across the room, if you understood the sentence you heard it must have been processed immediately and not held it in memory until you stopped walking. You may have understood it *less* but it was truly simultaneous.

          1. And no, that doesn’t just mean there can be background tasks. Or if it does, the term background tasks ceases to mean very much, because they can be more complicated than some people’s most complex foreground tasks if your mind is properly trained for that task. But what I mean is, there’s effectively no difference in doing two “easy” things at once and doing anything else while driving except for whether statistically, the bulk of the population can spare the portion of their attention required for the other task while maintaining an adequate level of skill at driving. It’s not all time-based-switching, some of it is just whether people have the capacity or whether their resources are insufficient to maintain good quality. Should people put 100% of their maximum attention on driving, to the exclusion of all else? Well, we could go into various philosophical arguments about safety being infinitely good or pascal’s wager and game theory, but logistically it makes more sense to reserve some level of attention for reacting to difficult situations like if a wreck occurs in front of you, rather than obsessing over remaining within 1mm of the center of the lane or whatever else you can do if you truly used 100% of your maximum attention on improving your driving.

        2. There is this guy that drives around our neighborhood in a van at like 60 mph, running red lights, and honking his horn like some sort of nutsack. To top it off his car is lit up like a christmas tree and his friend feeds people drugs while not wearing a seatbelt and both listening to a radio and responding back without using a hands free system. You might want to call him and have a word about his driving. I hear there is no city or town safe from these guys either. Crazy… I think the number is 911…

    8. On the one hand I agree.
      Distracted driving is a huge problem.
      Cars should not even have a radio. No, I’m not joking. If you are listening to music, you aren’t listening to the car. There is a WEALTH of information in that sound. Cars make lots of different noises that tell you how they are operating. And your brain can process queues without you explicitly stopping to think about road texture, wind, or other changes.

      No conversation either.
      Not with passengers.
      Not on the phone, hands-free or not.
      This isn’t because it stops you from hearing the car/road. It’s because multiple cognitive studies show that our mind creates a “conversation place” while we talk to people we aren’t looking directly at. We imagine the person we are speaking to, even creating facial queues and body language that reinforces our idea of the person we are talking to. It is unavoidable.
      It’s similar to how someone saying “seagull” will make you imagine one, whether you try to or not.

      That is distracted driving. You are daydreaming about a person instead of giving your full attention to driving.

      (Also, there is no such thing as multitasking. This is a lie your brain tells you, and has been disproven many times. At best, you are good at pausing one task to do another, then switching back. Or, you can push a task into “background reflex mode”, which is not the same thing.
      You cannot actively do multiple things at once.)

      However, while I disagree with the “-tainment” part, I FULLY support the “Info-” part.
      That screen can provide useul information to the driver.
      Navigation. Backup camera.
      A second rear-view with glare/headlight removal.
      Or even AR stuff like object detection with highlights.

      And it can serve MANY purposes when not driving without requiring you to have to link a phone/tablet to the car.

  2. My wife owns a 2017 Jazz. It does everything expected of it and more. It’s almost perfect. The one thing that lets it down is the infotainment unit. Worst UI ever, verging on dangerous.

    One example: The pause control is a 6mm square on the screen. You have to take your eyes and concentration off the road to use it. The old fashioned radio/CD players had nice big controls and switches. You could feel the difference without looking. Need to silence the car in a hurry? Just slam your palm into the volume/power switch and you’re done.

    I note that Volkswagen have finally seen the light on this issue:

    1. I’m all in favor of tactile buttons for infotainment in vehicles, but then you have to take your hand off the wheel. Steering wheel controls work great, you just take your finger off the wheel and no looking.

      1. Do you now? I’m just imaging you with your knee holding the wheel while you lean to the center of your car with both hands on your head unit. Sensationalism.

        In reality people glance at their head unit the same as they would a vintage radio with knobs do what they are gonna do with one hand and thats it…. literally I’d be surprised as heck if you could find someone that kept thier eyes glued on the road as if their life depended on it while adjusting a vintage radio knob.

        1. I used to spend very little time looking at the radio or the hvac controls. I do look at the instruments in the dash, so it’s not like I never glance around in a car – but it’s just touchscreens where you have to both look at the screen and look at where your hand is while using it even once you’ve gotten used to the controls. Even just in typing this comment, it was easier to look at the screen just to see what it’s telling me, instead of also having to look at it in order to use an onscreen keyboard or the like. And I’m not even trying to drive a car at the same time!

        2. I don’t.
          I operate the tactile switches on my dash without looking.
          Just like I don’t constantly look at the shift-knob every time to read the gear number, or look at the pedals.

          I DO glance at the screen when using navigation, or when it is in rear-camera-night mode. But that is no different than glancing at the speedometer or mirrors. It is to gather driving information.

          Because I’m driving.

          No music.
          No conversation, passengers or phone.


          If that seems unrealistic or “no fun”, then maybe you shouldn’t be driving.

          1. If you have to do all of those things… you probably shouldn’t be driving unless you have to. Because if by taking every possible advantage and devoting your full attention, you aren’t able to drive with such a statistically anomalous level of skill that you can place your tires within 1mm of where you want them to be, get 20% better mpg than the standard rating, arrive 10% sooner despite never breaking or even bending any possible traffic rule or convention, etc… then if you ever have a bad day or there’s an unusual difficulty, you will have absolutely nothing left in reserve and you’ll drive badly and risk a wreck.

      1. Maybe if your attention is so severely divided by a touch screen…. maybe the problem is you.

        Touch vs knobs are not a big deal as long as the buttons are large enough on both.

        1. Wrong. A physical control can be located/identified by touch and muscle memory. Successful actuation or state can be confirmed by feel.

          A touch screen with menus requires you divert visual attention from the road in order to work it.

        2. Even if the problem is me. There are many other “problematic people” like me who can find tactile buttons by muscle memory and touch but have to briefly look at a touch screen to know where to touch and a little longer to confirm if the touch was registered(I have zombie fingers; touch screens often don’t respond to my touch). It only takes 1 second of distraction to potentially cause an accident. That’s why many countries have banned operating a smartphone while driving.

  3. Infotainment system on my Honda is a combination radio, cassette, and CD player.
    I haven’t used the cassette player in years, and maybe a year since playing a CD.
    Though I could use a cassette adapter if I wanted to hook it to my phone 📱.
    The SatNav and the dashcam are standalone.

  4. I would like to control everything in my car connected to it. From turning off that annoying alarm and all telemetry, to control shift points and boost curves. Security in a car is less of a concern for me, because i buy used cars with low remaining value anyway. By that time, they should be hackable.

  5. It has controls on the steering wheel but none to mute the sound quickly. It has a button marked “source” which, despite the name, will turn off the unit if you hold it down for several seconds but by that time you are past the emergency situation you wanted full concentration for. Alternatively you can hold “volume down” button for several seconds. Neither of these methods give you instant silence or full control of your steering as you swerve to avoid a giant feral pig, a kangaroo, an endangered cassowary or any other large animal that wanders out of the rainforest or cane fields with no notice. I’d guess it’s the same for cyclists and pedestrians in a city.

    I just want to get my ambient sound level from Motörhead to library as soon as possible.

    As I said, bad UI.

    1. If you are messing with your radio at all… “to give you full concentration” you have an issue with your priorities, the same as people that blow their horns instead of avoiding collisions.

      The mute button is the last thing on my mind in a hazardous situation… on the other hand I’ll always reach for the hazards indicator. Because that keeps other people from hitting me, as well as warns them of danger ahead.

  6. I got a 2016 Jeep Cherokee as a loaner for a couple of days when my 2007 Expedition EL was in a dealer shop for transmission service.

    Three things made it easy to decide I’d never want to own one of those.
    #1. the seats were super hard.
    #2. the ride was so choppy that every little bump caused the vehicle to rock fore/aft and whack me in the back of my head with the irritatingly angled forward and not adjustable head rest.
    #4. the radio not only could not be turned off, whenever the engine was turned off and restarted, the radio volume would be reset to pretty loud. Did Chrysler get inspiration from “Max Headroom” where it was illegal for televisions to have an off switch? The OFF button only turns the big display screen off.

    There is a software update that makes it keep the user set volume level and some other changes, but still does not provide an actual OFF function for the radio. All you can do is turn the volume all the way down.

    1. No contest on your conclusion not to buy the modern cherokee though I have different dislikes. But the headrests are easy to reverse so that they lean backwards instead, the seats differ between trim levels, and so do the radio options. I’ve seen a couple of their other radios from that year range and you would have been happy with them.

  7. I figured this out when I bought my Honda years ago. Simply connect a USB keyboard and win+B starts the web browser. I was able to surf websites and play videos.

    Go ahead and hack it. Just remember the heating controls are integrated into the infotainment along with the speedometer. At least on mine. Hack it and you may lose all that and brick your car.

    For now I just keep a ‘rubber duckie” handy so I don’t have to stop the car , turn it off, open the door, and start it again to reset it when it crashes. The rubber duckie send Ctrl+Alt+Del to reset it.

    Fun times.

  8. I don’t link anything. Google thinks I’m in 3 states. NWS radar is all the WX I need. Watch before going.

    I’ve griped about pushbutton elevator / lift volume controls since the first ones appeared on aftermarket stuff. “Going up….. you have arrived at a higher volume”, done. I don’t even like rotary “pots” that are not position sensitive, having to turn more than the same angle which is very repeatable in milliseconds. A mute anything is just extra distraction. That pot is quick and accessible, 2 buttons in the wheel can augment if really needed. I still drive a stick. Don’t get me started with touch anything when it’s cold and I’ve got gloves on.

  9. Rather than hack a specific device, we should be making an open one that we have control over to begin with.

    We waste so much effort repeatedly hacking devices to keep new things supported.

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