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Comment by tjohns

15 days ago

> I wonder what happens if you disable the e-SIM (in the US) and then a safety recall appears via software update - do dealers have any way to update control modules besides OTA?

I would assume so. Even on older cars, service techs can typically manually push firmware updates over the OBD-II / J2534 port. Rivian's OBD-II port actually hides an Ethernet signal inside of it - so the interface is certainly there.

Fun fact: You can buy an Ethernet adapter directly from Rivian here to connect to the car's internal network: https://rivianservicetools.com/Catalog/Product/TSN00535-300-...

> Rivian's OBD-II port actually hides an Ethernet signal inside of it - so the interface is certainly there.

Nice. This is really normal now, for what it's worth - all of the European makes have moved this direction as well (DoIP over ENET). There's shockingly little documentation about Rivian online, though, probably because emissions regulation doesn't mandate it.

> Even on older cars, service techs can typically manually push firmware updates

Older cars have no concept of such updates.

Happy with my 70s and 80s and early 90s cars.

  • Actually almost any fuel injected vehicle can accept flash updates through the port to at least the ECU and PCM, frequently the BCU is also write enabled.

    • If there is a BCM. My previous 1995 GMC C1500 had a PCM and the automatic transmission was controlled by mechanical linkage to a hydraulic computer in the transmission along with shift solenoids from the PCM. It also had "throttle-body injection" with two injectors replacing the carburetor. The OBD 1 system would switch to "open loop control" with preprogrammed injection in the event of a malfunction which would make the thing challenging to drive until you fixed the problem. So very simple compared to the multitude of computers and control systems in use today.

      A nice feature on that system was that you could put a paperclip between two pins on the diagnostic port and it would blink out the trouble codes on the SES light.

  • You can adjust the ECU for these 80s and 90s cars and “flash” them like anything else. There’s just a lot less settings! Not sure about the 70s but I’m sure some resto-mods also allow for this.