from Hacker News

Ask HN: Why don't modern vehicles show detailed engine codes?

by client4 on 2/6/24, 1:25 PM with 8 comments

OBD-II is the standard for accessing vehicle ECU codes and is accessed via a specialized port. Many modern cars have a digital instrument cluster AND an infotainment center. Why can't I get detailed information about a check-engine light from one of these screens?

For context, I have a 2023 GMC pickup and had to attach my OBD reader to understand why I had an engine code.

  • by speedgoose on 2/6/24, 3:37 PM

    On Teslas, technicians can enable a service mode that show a lot of data on the dashboard. It’s not accessible to everyone and requires a password.

    My old i3 BMW also had a service menu that you could access after pressing a button for a while and entering a password that was some kind of checksum of the VIN.

    But an ODB2 dongle is probably something important to have in your toolbox.

    And for a new car, you may prefer to let the company fix it under warranty while you get a loaner.

  • by jqpabc123 on 2/6/24, 1:31 PM

    For the same reason some manufacturers have attempted to stop providing detailed repair specs.

  • by ndjshe3838 on 2/7/24, 8:18 PM

    Some possible reasons:

    * Better for mechanics as it’s standardized and they don’t have to figure out the UI of every car model to read the codes (if I were a mechanic I’d definitely prefer just plugging in the meter)

    * The debugging is decoupled from the infotainment/dash so it’s more reliable, it would be pretty dumb if you had to have a working infotainment system to read engine codes

    * An OBD meter is like $20?

    * Historically a lot of cars probably had no display for showing codes

  • by LinuxBender on 2/6/24, 4:11 PM

    Why don't modern vehicles show detailed engine codes?

    Reduction in chances the vehicle owner will take the vehicle into the dealership for servicing and up-selling.

    As a side note and FWIW many vehicles do have button/key combinations that will display this data. Youtube is full of videos that show how to enable displaying them and how to perform many undocumented settings on most vehicles. Even my 25 year old vehicle has debugging functions that can be enabled by holding in the odometer button, turning the ignition switch to ON and waiting 7 seconds.

  • by h2odragon on 2/6/24, 1:33 PM

    Don't wanna confuse the "normal people" with technical gobbledygook. Car dash displays need to be clear of distractions, presenting their information in a concise form that is instantly recognizable at a glance.

    https://mechanicbase.com/cars/dashboard-symbols-warning-ligh...

    Oh, yeah, we don't do that either.

    Prolly has more to do with someone getting paid to read those codes for you.

  • by is_true on 2/7/24, 5:07 PM

    Because brands want you to go to their service network and because of Bosch automotive service solutions

  • by brudgers on 2/6/24, 6:15 PM

    Becauae nobody would buy a $4090 package just for that feature.

    Because it would be of no benefit to repair technicians.

    Because everyone who wants to know the code behind the light can buy an OBD reader.

  • by giantg2 on 2/6/24, 5:15 PM

    OBD-I cars needed a special reader too - a paperclip.