[Walkabout]

What I found out about the Data Communication Module (DCM) on my RAV4 is that even after you opt out of any cellular services such as Entune and the SOS feature your car continues to send information to Toyota via the built-in cellular connection. They claim that you "may" receive a discount on your insurance (if you enroll for monitored driving reporting) based on your driving habits, but chances are you will be penalized for driving like I do! Just another reason to drop off the radar screen. So I made it a priority to disable such communication.

Disclaimer: You will lose some convenience and safety features by doing this modification you assume all responsibility for any damages, legal liability, inconvenience or injury that may occur.

In summary I pulled the fuse on the DCM and removed the internal battery. Presumably the battery is there to power the unit if you crash and destroy your 12 volt battery and want to send an SOS.

You can probably avoid the work I did on my car by removing the DCM fuse (shown below) and waiting for the internal DCM battery to die, but I have not tested this approach. The battery is pretty big for a cell phone so it may take quite a while. Verify that DCM is offline by the DCM status shown in the last photo below. Also be wary of using bluetooth as I mention below.

The DCM unit is located behind the HVAC controls on the dash. I made the job way more complicated by removing the center console which was not needed. The HVAC controls pop out using the plastic trim tools that are needed for all modern cars, apparently.

Pulling out the HVAC controls and other components. I took out the radio/screen which was not necessary.

The HVAC controls knobs look like this.

The DCM unit is the lower shiny rectangle. Find two hex bolts (10mm?) that hold the unit in. Remove the DCM and disconnect the wires and antenna.

The DCM unit with the battery cover off. I removed the battery on my car and replaced the unit.

Location of the DCM fuse in the footwell along with all the other colored fuses. It is well marked on the fuse box cover, I think it was 7.5 Amps. I took way more plastic off than was necessary (no manual used).

Once things are put back together you will see this display showing that there is no cell connection indicated by the image of a cell phone with the diagonal line through it.

One caveat, if you use bluetooth to connect your phone to the car DCM will use your phone to connect to the mother ship and presumably send your data. I only use my iPhone cable to connect to the car which does not have this effect.

 

[somms]

Have you confirmed your DCM is disabled from top pic you posted? Reason I ask is because I would think DCM should be dimmed out w/line thru similar to bottom pic found over at this thread: 2019 RAV4 Remote Connect, wifi hotspot and SOS feature non-functional

Is your SOS button now lit red and no longer functions when pressed?

 

[camfused]

Why did you have to take apart the dash and remove the DCM battery, if you popped the fuse? Wouldn't that stop power to the DCM and the battery quit after a short while?

 

[Colonel]

I feel its a problem that they are using my cell connection to push data. I am guessing in many of the EULA that you sign, click or approve that its in there they have the right to push that data. Which is why EULA's need simplified.

I wear a tin hat so this was very interesting to me because its getting ridiculous how much of our personal data we just give away. And yeah, you can get a discount by putting ANOTHER monitoring device in your car that reports back home. SMH.

I wonder how we can see what we "sacrifice" by doing this? I know opting out removes remote start and my wife says thats a non-issue. Obviously anything using the cell connection (S.O.S, and...?) will be disabled.

 

[Colonel]

Why did you have to take apart the dash and remove the DCM battery, if you popped the fuse? Wouldn't that stop power to the DCM and the battery quit after a short while?

He mentioned that in his fourth paragraph.

 

[Walkabout]

Have you confirmed your DCM is disabled from top pic you posted? Reason I ask is because I would think DCM should be dimmed out w/line thru similar to bottom pic found over at this thread: 2019 RAV4 Remote Connect, wifi hotspot and SOS feature non-functional

Is your SOS button now lit red and no longer functions when pressed?

somms, I had the SOS feature, along with in-car Wifi turned off right after I got the car by calling up Toyota or Entune support. I really don't have a need for my car to be connected since my phone gives me everything I want. I checked my SOS button and it does not light up but the SOS letters do show up in red.

I decided to leave the DCM unit connected along with the antenna just in case the vehicle software detected a problem and threw a fault that could cause warning messages, beeps, or require that I take the car to the dealer to reset the fault code. Worse case I assume my driving data is being recorded on the DCM which will never be sent to Toyota.

My first idea was to keep the DCM intact, disconnect the antenna, and connect an antenna "dummy load" to keep from burning out the DCM. The DCM sends power to the antenna and if it has no way to dissipate the energy from a disconnected antenna the unit can overheat and die. So I decided to keep all the electronics connected but depower the DCM so it was unable to transmit.

I assume that the software does not detect a problem with the DCM and hence does not flag the DCM icon as not functioning. But all of the above is conjecture since we can't know unless they share the software source code, and that is never going to happen.

 

[jazhanel]

This is ironic. You are trying to make the DCM go away. I am trying to get the Toyota App to work and it won't.

 

[Colonel]

This is ironic. You are trying to make the DCM go away. I am trying to get the Toyota App to work and it won't.

LOL! You can have mine....So tired of data scraping services.

 

[Spaceballs]

LOL! You can have mine....So tired of data scraping services.

Agreed. It’s lame... However I chose to let Toyota collect driving data, at least for now so the service folks can’t blame something stupid on my driving habits... and that’s why I think it was put there in the first place - sans bureaucrat meddling.

 

[RAV4h XSE]

You also need to disable the EDR. And shut off your phone while driving.

 

[Walkabout]

You also need to disable the EDR. And shut off your phone while driving.

Thanks for the input. Would you care to expand on those comments? I assume you refer to an Event Data Recorder, which sounds like it will send data through the DCM at some point.

 

[RAV4h XSE]

Thanks for the input. Would you care to expand on those comments? I assume you refer to an Event Data Recorder, which sounds like it will send data through the DCM at some point.
[

Thanks for the input. Would you care to expand on those comments? I assume you refer to an Event Data Recorder, which sounds like it will send data through the DCM at some point.

Event Data Recorders, standard in most new vehicles, record vehicle parameters like speed, rate of acceleration or deceleration, cornering (g-forces), and who knows what else. It’s similar to a “black box” recorder used in aviation. If the vehicle is in a collision, all the data immediately prior to the event wil be saved in the EDR. Law enforcement, lawyers, insurance companies, and the vehicle manufacturer can subpoena the data for accident reconstruction and perhaps use it in determining liability.

Smartphones know where you are at all times unless you’ve disabled all those features. They have accelerometers, gps, etc that pretty much tells anyone with access to the data your location and perhaps other information like speed.

Have a smart watch? Shut it off.

Disabling only DCE does not shield you from all this data collection.

 

[Colonel]

Disabling only DCE does not shield you from all this data collection.

But makes it much more difficult for people/companies/services to harvest.

 

[thefranchise713]

Thanks for posting this. I'll have to dig out my fuse panel diagram and look for a DCM fuse again. I must have missed it the first time. If you have yours handy, can you repost it with which fuse takes out the DCM?

I'm going to see if I can pull the fuse alone and let that battery die out. I'm actually impressed they put a battery in there for the crash contingency, nicely done. But I'm the same on the data scraping as you.

The Event Data Recorder doesn't really bother me. I just want to stop the active transmission to Toyota. And yes, I've opted out of Remote Services, I just want the car fully off the grid.

 

[Walkabout]

The fuse box you are looking for is right above the driver's left footrest on the floor. Not easy to see, it's best to stand on your head Here is a photo of the cover that shows the 7.5 amp DCM fuse about 2/3 of the way down on the left column. Let us know how it works pulling the fuse. Once you see the cellular connection logo appear as disabled on the upper right corner of your display you should be offline.

 

[somms]

Once you see the cellular connection logo appear as disabled on the upper right corner of your display you should be offline.

Keep in mind the cellular connection is only monitoring the status of your personal cell phone connection. Unless DCM is 'dimmed' out w/line it is still actively communicating and reading back wireless signal strength according to the owner's manual...

 

[rav4awesomeness]

Am i missing something
What's wrong with the DCM on?
Data mining???
Hackers?
Privacy?

If my car was stolen, I would like the DCM to be ON, to be able to locate the vehicle...

What do you loose if the DCM is Off???

thanks

 

[thefranchise713]

The fuse box you are looking for is right above the driver's left footrest on the floor. Not easy to see, it's best to stand on your head Here is a photo of the cover that shows the 7.5 amp DCM fuse about 2/3 of the way down on the left column. Let us know how it works pulling the fuse. Once you see the cellular connection logo appear as disabled on the upper right corner of your display you should be offline.
View attachment 150259 View attachment 150259

Thank you! Will report back.

 

[thefranchise713]

Well, crap, I did this tonight with some success but eventually aborted mission. Let me explain...

The fuse was where it was promised (thank you again.) The fuse put up a fight, but eventually I got it pulled.

Turned on the car, all looked good. There were three main changes for this "failure mode" of the DCM.

• First, the LEDs surrounding the SOS button were completely dead. Traditionally, with Connected Services set to Active, the red light would pulse briefly before the green light would stay on steady. With Connected Services off, it would go Red-->Green--> and then completely dark. Now, the LEDs never pulsed. At all.
• Second, the SOS button was completely dead. Previously, even if the services flag were OFF, I'd get an audio prompt asking me if I wanted to restore services.
• Third, and here was the problem, disabling the DCM also takes out the front right channel of the audio.

When I turned the car back on, I knew the audio immediately sounded weird. So I pushed the balance in the audio settings to full front right. Sure enough, this is where my audio went completely absent. Restored the fuse, and my audio came back as well.

That was a huge disappointment, but in retrospect, not wholly unexpected. When I pressed the button to reach the Connected Services folks to have the services disabled, I noticed that audio only came out of the front right and found it weird. I'm guessing Toyota has the DCM, which itself has power, in-line with the speaker so it removes a failure point (an unpowered audio processor) in the middle if the entire 12v system is depowered in the event of a crash. Smart, but creates the problem above--the DCM is a failure point for the front right channel of the audio system.

So for now, the fuse is returned, but for 30 glorious seconds it was nice to have the car fully off of the grid. C'est la vie.

 

[somms]

When I pressed the button to reach the Connected Services folks to have the services disabled, I noticed that audio only came out of the front right and found it weird.

Budget aftermarket stereo retrofit for 6 speaker RAV4...

Sorry This

www.rav4world.com

FWIW: On 6-speaker non-JBL DCM audio feeds thru right front door + dash speakers (wired in paralllel) while 9-speaker JBL output DCM audio only thru right dash speaker as show in link above...