Free Theft Protection - The OBD II Port Removal
 

Since we all want to reduce the chance of theft, and because we know that access to the OBD II port is the primary mode of attack for low-effort thieves, why not remove that access.

The factory OBD II port is held in place with two clips that are easily depressed from the cabin-side. I did it with my fingers. Once depressed, you can remove the OBD II port from the rear and gain access. That access looks like this:

https://hosting.photobucket.com/imag...211_235540.jpg

From here you can either intercept data wiring to route to an interrupt switch (like a 4-pole toggle to remove data access), or you can hide this harness, or you can de-pin, whatever you want to eliminate useful access for a thief.

There are only eight wires used in this 2023 1SS, as shown here:

https://hosting.photobucket.com/imag...211_235456.jpg

And the schematics for this port are as follows:

https://hosting.photobucket.com/imag.../OBD_Image.JPG

https://hosting.photobucket.com/imag...OBD_Pinout.JPG


Removing this port from the socket and hiding it is free. It may be enough to deter a thief who is looking for an easy job. A missing port may cause them to go looking, or may deter them to look for an easier job. You can hide the port in several locations and then simply unhide to provide access to a shop or tech for actual service. If you have a range device to deactivate AFM, hiding the port may be handy if you don't like the light. Whatever your reason, this is a free step that may just make the difference between a 60 second job and a walk-away abort.


You may also feel like installing a fake port in place of the OEM port is a good deterrence, since a thief will notice the missing port andmay go looking. I would be better if the port had a functional 12V and ground so their tool would power up. You could even add some 10k ohm resistors between the data pins so it looked like something was there. Good news, you can buy the OEM port, pins, and retainer for a few dollars form Mouser Electronics.

https://hosting.photobucket.com/imag..._Connector.JPG

And if you want to pin this to provide voltage so it appears as if it might work, and looks like it has pins, you can get the pins and retainer here also.

**UPDATED** The Pin information I shared previously is reported to be incorrect. I apologize for that confusion, I was referencing service information and the pin compatibility on Mouser. Below is user confirmed pin compatibility:

WM3324CT-ND
https://www.mouser.com/ProductDetail/Molex/0504208000

https://hosting.photobucket.com/imag...D_Retainer.JPG


I have ordered the items above and will report back once received for a verification of fitment, but the part number is from the GM service manual and looks identical.


I do not recommend you do the following. This is the "do not do this" portion of the post:

Once you have pins and the replacement OBD II port, there is nothing stopping you from re-wiring this port with reverse polarity, meaning you put 12V on the ground and signal pins and then ground the 12V pin while serving the 12V side from a dedicated fuse at the battery (sized for the wire used). Doing this is not advised as it would destroy the tool being used to steal your car, or a tool used by an actual service tech to fix your POS. The latter is why a cover indicating access is not advised is strongly recommended.

https://hosting.photobucket.com/imag.../OBD2Cover.PNG

Even with a cheap cover indicating that access is not recommended, you may be liable for damages that occur to scan tools that are connected to your booby-trap. Don't do this, even if you're tempted to. PSA over

The cheap cover may be recommended with the hidden port, to protect the pins from being shorted out. This depends on where you relocated the port.

I may consider moving the real port and installing a dummy in its place. As far as powering it up for their device, not a chance. There’s close to zero chance a Camaro thief will get on their hands and knees looking under the cramped dash to find it. I own the car and the thought of dicking around under there incites pain.

Sounds look a good idea. I personally don't care about thieves and they deserve what they get. If I take my car in, I'll just put the original back in place.


There should be instance where my car would go into a service center without my knowledge.

I'm with you. I will certainly pin the dummy so it looks legit, but I'll put extra pins in unused places and omit the 12V pin so if they were somewhat smart they would realize the port won't work as pinned.

Since the threat of theft is very low for me, a simple solution is all I really need.

So gotta ask….how are the bad guys using the obd port to steal the car?..

Love the idea I just don’t understand the why of it.

*** flame proof jacket on ***

its used to clone a key

I would like to understand this a bit further before going for another solution. I thought that the way to steal our cars (or any modern car) is by intercepting the signal emitted by the keyfob.

We've had plenty of threads and discussions on the topic on this forum in recent weeks, in FB groups, Reddit, etc. The consensus is that the OBD port is used to deactivate OnStar as well as making keys, and getting around any other security. You can change whatever you want with access, it's how Tuners make changes as well. These aren't your joy riding thieves, these are people looking to make money (hence the investment in tech). Reports hover around 60 seconds with minimal damage to the car (just entry).

People are discussing pedal locks, steering wheel locks, removing fuses, disconnecting the battery, fuel kill switches, starter kill switches, etc. But those methods require you do something inconvenient every time you drive the car. For a weekender, probably fine. For a daily driver like me, I won't use it if it's not easy and convenient, and this is the ultimate convenient solution as I don't have to do anything else. If the port is being used, eliminate the port. No need for clubs or kill switches.

There is also easy access under the dash to the BCM - which I don't like either. So I'll end up making a cover to hide all of that using security screws, to further frustrate and make my car not worth the effort.

The little secret to not getting nicked is to just be more difficult than the next guy. Thieves will move toward easier prey, as there is plenty of it around.

Can people use different tech to copy a key? Sure, it is also a sophisticated attack but one that does require your presence. With enough persistence and patience, any car can be nicked. What I am doing here is just reducing the success rate with an attack that we know is used and doesn't require you to be around.

OBD2 locks are apparently also a thing -- which could be interesting to put something like this on top of a replacement OBD2 port (and particularly a "rewired" one, to reduce the likelihood of unintended damage to "friendly" equipment).

https://a.co/d/aD2V9Yo

https://www.amazon.com/dp/B0BRF5D18D

https://www.amazon.com/dp/B09NDVY3PP

Disclaimer - the $180 price on this last one seems a little crazy, but shared as food for thought!

EDIT:

And items like these add some additional possibilities for installing a spoofed OBD2 port:

12-inch cable with connector: https://www.amazon.com/dp/B0B213F7N1

Extension cable: https://www.amazon.com/dp/B09GBGNC87

Y-cable: https://www.amazon.com/dp/B071L8W7Q7

Correctly wiring just the power/ground to the replacement port and then adding a plugin device that has an illuminated power indicator might further add to the confusion for thieves.

Another creative option: some off-the-shelf dummy OBD connectors have a piezo siren that activates if a device is connected to the port. A hidden button has to be pressed to deactivate the siren.

I like the way you think. The other connections are all data bus wires, so there is nothing to power on those pins. A small current sensor could be used to identify when something is plugged into the port and then trigger a piezo siren.

A port lock is likely cheesy and easy to defeat. Those keys are probably generic. Maybe a lock over a dummy that has some power from a cap to make it seem like it worked then it didn't.

The little things add up and makes it that much more difficult. Relocating the port and putting a lock on the dummy might be enough for opportunistic thieves to move on to the next car.


The longer they spend on one car the more likely they can be caught. Especially if the tools they are using allow for a real quick getaway.

How about an OBD splitter? The end replacing the original OBD can be modified to supply power only, the other end zip tied up under the dash, and would also act as an extension when you need to use the real OBD port. Thoughts.

OP -- did you find a good place to relocate the OBD port?


I think buying a dummy one and relocating the oem one is a nice simple deterrent.

https://hosting.photobucket.com/imag...OBD_Pinout.JPG
Cut the blue and the yellow wire (pin 6 & 12) and install a double position single throw switch (DPST). The port will still be hot, but they won't be able to do any communications with any of the modules with out the CAN data bus.


https://www.littelfuse.com/~/media/i...pst-on-off-jpg
Hide the switch somewhere discrete and just flip it on when you need to connect to the OBD connector.


If you are really worried you can install a TPSD and cut the green wire on pin 1 too and wire it in, just to be sure.