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How to disable cellular connectivity in a Gen 2 (2016-2019) Chevy Volt

27 points by bobbiechen 2y ago

atoav 2y ago
Step 1: vote for people who will make it mandatory that this type of "service" is opt in
- tivert 2y ago
  > Step 1: vote for people who will make it mandatory that this type of "service" is opt in That's not good enough. It needs to be mandatory that these services be implemented as physical, user-removable modules. A software opt-in can never be really trusted.
  - M95D 2y ago
    This service is required by law in EU [1]. AFAIK, it is still legal to remove it after the car is bought, but I read somewhere there was a proposition to make that illegal too. In that case the car won't pass periodic inspection without it. Sometimes I wonder if Somalia or Afganistan accepts immigrants... [1] https://europa.eu/youreurope/citizens/travel/security-and-emergencies/emergency-assistance-vehicles-ecall/index_en.htm https://europa.eu/youreurope/citizens/travel/security-and-em...
- deleted 2y ago
  [deleted]
deleted 2y ago
[deleted]
thegrim33 2y ago
Would maybe be a neat idea for someone to create a site that's a repository of instructions like these but for as many makes/models of cars as possible. So you can just put in your car's info and get instructions on how to physically disable as much tracking / collection as possible.
- mik3y 2y ago
  I've been interested in doing this as a side project too, ever since "unwiring" my jeep in a similar fashion (rip out modem). My quick-and-dirty idea was to stand up a Discourse forum with categories for each make, threads for each model (or possibly model + model year range pairs). If anyone wants to collaborate / provide some extra motivation, hit me up..
deleted 2y ago
[deleted]
tivert 2y ago
Does anyone know how much power the cellular modem uses to transmit? I wonder if it would make sense to use a higher-rated dummy load like the one below? I'd imagine the extra margin would make it less likely to fail eventually. https://www.amazon.com/dp/B08K2GN27R/ref=twister_B08K2WHVXS https://www.amazon.com/dp/B08K2GN27R/ref=twister_B08K2WHVXS
steelframe 2y ago
I simply yanked the Data Communications Module (DCM) fuse on my GR Corolla, but that has the unfortunate side-effect of also disabling the microphone. That means the only way for me to take hands-free phone calls is with the speaker phone option, so I've simply stopped taking phone calls at all when I'm driving. When researching how I might be able to do something more surgical I ran across this post by someone who did it with their Tacoma: https://www.tacomaworld.com/threads/simpler-solution-for-disabling-the-dcm-telematics-silencing-antennas.821649/ https://www.tacomaworld.com/threads/simpler-solution-for-dis... Reading this HN post on the Chevy Volt it's starting to look to me like the general approach of installing a 50ohm "silencing antenna" could end up working for a lot of different cars out there. I'll certainly be giving it a try on my GR Corolla now so I can get the microphone back while still keeping the DCM disabled.
- tivert 2y ago
  > I simply yanked the Data Communications Module (DCM) fuse on my GR Corolla, but that has the unfortunate side-effect of also disabling the microphone.... > Reading this HN post on the Chevy Volt it's starting to look to me like the general approach of installing a 50ohm "silencing antenna" could end up working for a lot of different cars out there. I'll certainly be giving it a try on my GR Corolla now so I can get the microphone back while still keeping the DCM disabled. I started researching this again because of this, and it looks like you may need to watch out for "Dark Draws" (https://www.reddit.com/r/subaru/comments/1bn1c3a/dcm_bulletins_updates_and_clarifications_1531824r/ https://www.reddit.com/r/subaru/comments/1bn1c3a/dcm_bulleti...) where the DCM trains the battery because it couldn't make a connection. Apparently this has been a problem with some 3G based units when they shut 3G down. It looks like Subaru, at least, has made a replacement DCM "bypass" box to allow the DCM to be removed without disabling other car features: https://static.nhtsa.gov/odi/tsbs/2024/MC-10251102-0001.pdf https://static.nhtsa.gov/odi/tsbs/2024/MC-10251102-0001.pdf
  - steelframe 2y ago
    Thanks for the heads-up about that. If I go this route then it looks like I'll want to measure battery drain both before and after installing the silencing antenna.

27 points by bobbiechen 2y ago

atoav 2y ago

Step 1: vote for people who will make it mandatory that this type of "service" is opt in

tivert 2y ago
> Step 1: vote for people who will make it mandatory that this type of "service" is opt in That's not good enough. It needs to be mandatory that these services be implemented as physical, user-removable modules. A software opt-in can never be really trusted.
- M95D 2y ago
  This service is required by law in EU [1]. AFAIK, it is still legal to remove it after the car is bought, but I read somewhere there was a proposition to make that illegal too. In that case the car won't pass periodic inspection without it. Sometimes I wonder if Somalia or Afganistan accepts immigrants... [1] https://europa.eu/youreurope/citizens/travel/security-and-emergencies/emergency-assistance-vehicles-ecall/index_en.htm https://europa.eu/youreurope/citizens/travel/security-and-em...
deleted 2y ago
[deleted]

deleted 2y ago

[deleted]

thegrim33 2y ago

Would maybe be a neat idea for someone to create a site that's a repository of instructions like these but for as many makes/models of cars as possible. So you can just put in your car's info and get instructions on how to physically disable as much tracking / collection as possible.

mik3y 2y ago
I've been interested in doing this as a side project too, ever since "unwiring" my jeep in a similar fashion (rip out modem). My quick-and-dirty idea was to stand up a Discourse forum with categories for each make, threads for each model (or possibly model + model year range pairs). If anyone wants to collaborate / provide some extra motivation, hit me up..

deleted 2y ago

[deleted]

tivert 2y ago

Does anyone know how much power the cellular modem uses to transmit? I wonder if it would make sense to use a higher-rated dummy load like the one below? I'd imagine the extra margin would make it less likely to fail eventually. https://www.amazon.com/dp/B08K2GN27R/ref=twister_B08K2WHVXS https://www.amazon.com/dp/B08K2GN27R/ref=twister_B08K2WHVXS

steelframe 2y ago

I simply yanked the Data Communications Module (DCM) fuse on my GR Corolla, but that has the unfortunate side-effect of also disabling the microphone. That means the only way for me to take hands-free phone calls is with the speaker phone option, so I've simply stopped taking phone calls at all when I'm driving. When researching how I might be able to do something more surgical I ran across this post by someone who did it with their Tacoma: https://www.tacomaworld.com/threads/simpler-solution-for-disabling-the-dcm-telematics-silencing-antennas.821649/ https://www.tacomaworld.com/threads/simpler-solution-for-dis... Reading this HN post on the Chevy Volt it's starting to look to me like the general approach of installing a 50ohm "silencing antenna" could end up working for a lot of different cars out there. I'll certainly be giving it a try on my GR Corolla now so I can get the microphone back while still keeping the DCM disabled.

tivert 2y ago
> I simply yanked the Data Communications Module (DCM) fuse on my GR Corolla, but that has the unfortunate side-effect of also disabling the microphone.... > Reading this HN post on the Chevy Volt it's starting to look to me like the general approach of installing a 50ohm "silencing antenna" could end up working for a lot of different cars out there. I'll certainly be giving it a try on my GR Corolla now so I can get the microphone back while still keeping the DCM disabled. I started researching this again because of this, and it looks like you may need to watch out for "Dark Draws" (https://www.reddit.com/r/subaru/comments/1bn1c3a/dcm_bulletins_updates_and_clarifications_1531824r/ https://www.reddit.com/r/subaru/comments/1bn1c3a/dcm_bulleti...) where the DCM trains the battery because it couldn't make a connection. Apparently this has been a problem with some 3G based units when they shut 3G down. It looks like Subaru, at least, has made a replacement DCM "bypass" box to allow the DCM to be removed without disabling other car features: https://static.nhtsa.gov/odi/tsbs/2024/MC-10251102-0001.pdf https://static.nhtsa.gov/odi/tsbs/2024/MC-10251102-0001.pdf
- steelframe 2y ago
  Thanks for the heads-up about that. If I go this route then it looks like I'll want to measure battery drain both before and after installing the silencing antenna.