My DCM disconnection odyssey.

If you connect with Bluetooth or Android Auto, Google knows what car you were in.

 

Well. I wasn't going to get into this but all blue tooth, wifi etc all have a unique MAC address which can be seen as devices get close to eachother. You can often, but not always tell the manufacturer and the model of the device from the MAC address.

Edit: with literally no effort at all and if you never connect your phone to your car, the data will show that you get into a vehicle and drive someone every day. From there is a safe assumption that, that Mac address your phone sees during that drive is your car and the place you go is work. (Years ago my phone even asked me - do you want to add this place as "work" - so convenient)

They do all kinds of stuff with our data because algorithms do it for them and the more information they have the better we can be monetized.

 

This is starting to sound a lot like “Why bother disconnecting the DCM” rather than “How to disconnect the DCM.”

 

The goal is to not be an easy target for various dragnets and mass surveillance requests. There are search engines for connected things and there are search engines that help you geolocate, it is only a matter of time until someone go looking for a 4Runner to steal based on DCM connection.

 

Looking at the pinout, three of the pins are likely to disable it if disconnected (VCC, DATA, and CLOCK). For the other five, disconnecting GND may be unreliably effective and the remaining four probably won't kill it. Removing the whole chip would be almost as easy and certain to work.

 

Good day all,
I'm on the same journey to find a way to disconnect the DCM while keeping the necessary entertainment functions.
I'm driving around with the fuse out, but as you know, the microphone no longer works.
I am also of the belief that asking Toyota not to track or send data from my vehicle is useless. They will do what they want discreetly no matter what I demand.
If we leave the DCM connected, Toyota or big brother can easily decide they don't want us driving the car anymore and simply take away our right to drive with the flick of a switch.
no thanks.
Luckily, I came across this site: AutoHarnessHouse.com which makes head unit harnesses for Toyota's and Subaru's for after market devices. Interestingly, they make Starklink DCM bypass so that Subaru owners can disconnect their DCMs while keeping their speaker and microphone functionality. See here:
https://www.autoharnesshouse.com/69018.html

I emailed them, basically begging for the same type of Harness for 5th Gen 4Runners. I don't know if they will reply, but if enough people cry for help, they may relent and realize there is an actual financial benefit to manufacturing such a harness.

Let's give it a go.
Thanks,
MadMax20

 

This is what we need. There is definitely a market for it. Sending them an email myself.

 

I just sent them an email...

 

Not quite. Opt-out with Toyota will not protect you from FISA court ordered monitoring, but it will protect you from commercial spying.

That is, there is no reason to also not opt-out. It will not harm you and may help in certain circumstances.

 

I joined the others in emailing AutoHarness. Their reply is encouraging:


We've been working on developing this for the past year, but it has been difficult to find the connectors that we need to do it. I know there is a large market for this and I will add your name to the list so that we will notify you once we can provide it. I think we're getting close to being able to provide a plug and play solution that would retain the front speakers, but the handsfree/bluetooth microphone will be a later version (which we are also working on)
In the case of some of the slightly older models, we've been able to successfully build this part so I think there's hope that we'll have it done soon.

 

What did you say in your email?

Im also interested and will email them

 

Hi "T in Texas",
here is the text of what I emailed to them.
....
Good day,

I have 2024 4Runner SR5.
I am looking for a wiring harness to bypass the telemetrics module (DCM).

I am driving around with the DCM fuse out, and because of that, the microphone does not work.
I understand that if I disconnect the DCM, that I would also lose the right speaker as well as the microphone.

Can you build a bypass harness, to disconnect the DCM while keeping the speakers and microphone?
If so, there are an awful lot of us 4Runner owners who would gladly purchase one. In my case, I would buy 2, my wife has a 4runner as well.

Thank you for your time.

 

done...just sent

SUBJECT: Toyota 4Runner wiring harness to bypass the telemetrics module (DCM)

Hello,

Saw your contact info on the 4Runner forum here

https://www.4runners.com/threads/my-dcm-disconnection-odyssey.25104/page-8#post-613872



A few of the guys are talking about your products for Subarus, and hoping you have one for the 5th Gen 4Runner.



I have a 2024 $Runner TRD Pro and would be interested in a harness to bypass the DCM while keeping the microphone usable.



If this product becomes available, please let me know…and I’ll make sure some other 4Runner owners with privacy concerns hear about it too



Thank you

 

This is the response I received:

"We've been working on developing this for the past year, but it has been difficult to find the connectors that we need to do it. I know there is a large market for this and I will add your name to the list so that we will notify you once we can provide it. I think we're getting close to being able to provide a plug and play solution that would retain the front speakers, but the handsfree/bluetooth microphone will be a later version (which we are also working on)

In the case of some of the slightly older models, we've been able to successfully build this part so I think there's hope that we'll have it done soon."

Brian
--
Brian Doll
Technical Support and Sales Engineer
inquiry@autoharnesshouse.com

 

This AutoHarness development is an exciting prospect.

 

I provided them with this thread so they could read everyone's concerns and hopefully help in their coming up with a solution for us.

 

Great! They should also have a look at these threads on the Tacomaworld site.

https://www.tacomaworld.com/threads...the-dcm-telematics-silencing-antennas.821649/

https://www.tacomaworld.com/threads/disabling-the-dcm-not-another-tin-foil-thread.825734/

https://www.tacomaworld.com/threads...e-i-can-find-the-trucks-3g-lte-module.660426/

 

I just removed the DCM fuse.

#1 DCM light is off. Check
#2 Microphone option is no longer highlighted when navigating. Check
#3 I do not appear to have lost any speakers that I could tell. Which one am I supposed to lose and are we sure that's for all models? I've got a 2024 TRD Pro.
#4 I would love to physically disable the Bluetooth. Anyone know how?
#5 I'm concerned how much information a person (mechanic, hackers, law enforcement, etc.) could get if they had unrestricted physical access to the vehicle. I'm assuming my GPS is logging everywhere I go, for example, and that once somebody has physical access they could see my history. Removing the DCM helps to prevent it from "phoning home" constantly with everything I say and where I go. But once accessed physically, the only thing I've really disabled is what I say in the vehicle is no longer being stored in some black box of the vehicle.

Thoughts?

 

Follow the third link in the post directly above yours.

 

Brian, the person that runs the website and the engineer behind the harnesses is a great guy and willing to work with you to find a solution.
I have bought from him earlier. I will shoot an email to him to see what he has to say on the topic.
PS:My 4runner is old enough that it does not have any DCM module in it.

 

Another email sent to try to obtain a solution to this.

 

3. Haven’t heard of speakers being lost but that’s just me.

4. BT is likely a function of the head unit, you’d have to just turn it off or don’t use it.

5. I would expect no GPS logging unless you turn on the breadcrumbs option. Whether it does that sneakily is a great question but it doesn’t seem accessible from the head unit like that.

But anything you save on the head unit could theoretically be grabbed from addresses, maybe contacts if you synced those via bluetooth (actually that’s something people often forget to do when getting rid of a car)

albeit valet mode would probably offer basic protection from a drive-by check but not a forensics professional, but by then your head unit is coming out.

I think the saving grace here is that the “threat” we’re working with here is largely remote, it’s relatively easy for an organization to pay money to get data - but by the time you get to someone pulling the head unit that requires quite a bit of effort and commitment from whoever wants that information. One would probably go looking for data at any other web services you may use before busting out the tools

 

Interesting. I supposed all that would be required is a laptop with the right software and access to the OBD2 port.

 

I've been reading this thread with interest.
I have a question that may involve the DCM.

I have a 2023 corolla hybrid and I immediately bought a new head unit on the car (Alpine)
Every time I go on vacation for a week, the battery drains .

Is it possible that the DCM on the Toyota needs the original head unit? Could it be possible that if I have an after market head unit, the DCM just keep trying to poll the head unit without success and just eventually drains the battery?
Any help with this would be appreciated

 

Normally when something goes wrong, the most recent change is related. But to track down a parasitic drain you gotta check the power draw of different modules. If it's the DCM it'll be drawing a significant amount of power when the vehicle is off and after things should be asleep.

 

I took it to a dealer and this is what they wrote:

 

If it was a DIY job, I would check on their suspicion of the DCM wiring tapped. You could also try removing the DCM fuse and seeing what changes.

You could also take it back to the installer if a shop did it if something important dies with the DCM because normally you should be able to pull the DCM fuse without any negative effects. (except maybe losing the microphone)

 

I think the dealer said the I lose the microphone and the speakers

 

Microphone if the vehicle was stock.

Speakers if their guess that the speakers were wired into the DCM wiring is correct. It sounds like the wiring for the speakers will have to be changed to feed off of a different circuit if that is the case.

 

Well after that dealer report I took it back to the audio shop and it didn't seem like there was another circuit that they could put the equipment on.