how to disable the DCM/Telematics unit in the car

Toyota already has their own though. You get Marketing emails from Toyota. You opt out and they just change the name to transactional emails that cannot be disabled. They even include the same, useless, marketing opt out link.

 

@shouser :Cool.

 

Polk County Texas man Phil Sify is taking Toyota to court over excessive data collection:

 

Sorry to resurrect this.

Does changing the URL have the same net effect as disconnecting the DCU and jumping the leads? That is, is the car unable to communicate to upload -OR- download information at all? Or is this just an interim measure to take before disabling the DCU? Will I, for instance, have normally functioning GPS that receives traffic updates, ads for gas stations and fast food, etc.? Or will I need a stand-alone dumb (e.g., off-line) GPS unit for navigation?

 

I pressed the help button the day I picked up the car and told the nice lady I wanted to delete any of that connectivity. It seems to have worked. I use CarPlay for navigation. Android Auto is also an option. No subscription money to Toyota. I'm not crazy about the prospect of removing a bunch of stuff to do that. It still only has 9000 miles on it.

 

Fantastic!

I'm buying a brand new Prius tomorrow. I know that I want to disable the DCU because I have a deep distrust of telematics (same reason I hate Flock cameras and Palantir, why i have a Faraday bag for my phone, always use a log-free VPN, etc.), but it's going to take a few days or weeks to get the wiring sub-harness, and then get it installed. So that should be a very good interim measure.

Yeah, I know it sounds like tin-foil-hat territory, but... I absolutely do not trust anything related to Big Data.

 

It was the middle of the winter, a new car, I just wasn't motivated.

There's a sticker on the infotainment area. Don't let the dealer activate it. Even though I didn't, pressing the Help button and opting out seemed to do a little more. I have no idea.

So what color?

 

I Disabled the DCM through the menu on my 2024 Prius. I later contacted Toyota Support and asked them to Opt Out of Communications. The person I talked to said that they were unable to do it right away, (because I disabled it.) and said that they needed to get their technical support to disable it. I KNOW that they accessed my car REMOTELY because some of my settings were altered. WHICH MEANS that even though it is Opted Out, it is still transmitting and able to be accessed by Toyota Support REMOTELY! So when they want to disable your car they can. In a previous post I gave a link to the World Economic Forum showing that Toyota is a member.

 

Thanks for the info. I did try removing the DCM fuse, however it affects too many other things so I put it back in. I did buy a DCM Delete Harness from Auto Harness House Toyota DCM/Safety Connect Bypass Harness - Fits 2020+ Toyota Vehicles . So far I haven't installed it because I am under warranty, however if the Canadian government passes Bill C-22 requiring all Communications Devices to be Tracked I will install it immediately regardless of possible Warranty issues.

 

Does this actually work in terms of stopping the car from sending out user data?

Have you actually tried it? We're you able to confirm that the data flow has stopped?

 

I tried to change the url on my car and couldn't.

 

What are we looking at here?

 

I had a bit of a different experience from most people. Here's my process:

1. signed up for connected services and installed the Toyota app on my phone (and disabled all permissions except "detect nearby devices" from the app)
2. set up a profile and waited for the car to sync all the settings, and drove around for a couple days like a good little driver just in case my driving data ends up somewhere
3. did not opt out of connected services or data transmission
4. removed the DCM (which was so much easier than the available tutorials/videos make it seem)
5. zip tied all the loose wires together
6. did not remove any fuses

After I put everything back together and started the car up, I noticed a few things:

• car info is no longer syncing to the Toyota app, and the app says the last update happened the last time the car was on with the DCM installed
• the navigation map still works fine, although it seems less accurate than before (jumps around sometimes and struggles to know exactly what direction I'm going). It still shows charging locations, all the map data, and everything else that I saw before removing the DCM
• speed limits/road signs still show up in the main display
• I can't search in the navigation window, even using the keyboard... if I tap the magnifying glass search button in the navigation window, a "Microphone is disconnected" error pops up and nothing else happens
• when I start the car, it remembers my profile and tries to sync settings, but doesn't seem to be able to (except...)
• today after I parked at work, the car said my profile was synced successfully (????)

I'm not sure how it was able to sync my profile without the DCM unless connected services is communicating through another module, or if it synced with my phone, or if it just knew I was at work. I'll have to do more testing this week to figure it out. In the meantime I've disabled the app completely on my phone.

 

I think the dongle mentioned above will restore use of the microphone, if desired.

Road signs is local, I believe.

I don't think WiFi is part of DCM. Probably head unit. To access my dashcam via WiFi, I have to disable CarPlay which apparently uses WiFi. This still worked with the DCM removed. If you didn't use CarPlay could you disable WiFi via a menu? Maybe.

 

Can you elaborate on the dongle that you have?

 

Road signs happen in two ways depending on if you have a Drive Connect subscription or not.

1. With subscription: The car uses the Toyota navigational data. This has pluses and minuses. On the plus side, you are not going to get spurious indications(explain more later), and you're going to have a speed limit indication even in stretches without a sign. On the minus, you might get incorrect displays in road construction.

2. Without subscription: The car uses the camera behind the rear view mirror to look for actual road signs. The plus side on this one is that it reads the temporary speed limit signs around road construction and is more likely to display the correct speed limit. The minus is that the car needs an actual sign to look at. If you turn onto a road and the next speed limit sign is 10 miles away, you're not going to get an indication until you get to it. You also can get spurious readings. When I was in Chicago last year, I was driving on a freeway with a frontage road right alongside. The car would sometimes see the speed limit sign on the frontage road and use that.

 

So after further testing, it looks like there is some kind of inertial navigation + best fit guessing happening when there are no GNSS updates. The car misread one of my turns and thought I was offroading last night. Now it thinks I'm on the other side of the city. But the speed limits in the primary display bounce between the limits from the map and the signs it sees on the road. It doesn't seem like it's one or the other.