I’m new about cars and would like to know if OBD2 devices like ELM327 are able to send the car alarm to a smartphone app, like Torque or OBD Car Doctor. So, instead of the car alarm making noise, the car alarm is redirected or sent to the smartphone.

Any links to learn more about this specific topic?


  • How would the Elm27 communicate with the smartphone? or would you use a device - a second phone for example, to send via gsm or just rely on a wifi signal - for which you would need access.
    – Solar Mike
    May 7 '17 at 19:25

Just a few days ago, I was successfully able to Integrate tk306a OBD with my car, it has all those functionalities to communicate with a custom cloud and an application. I can setup my own custom alerts, alarms, geofences, etc

  • from the info about the device, you need a sim card for this functionality but it does not support 3g or 4g.
    – Solar Mike
    May 7 '17 at 20:10
  • @SolarMike Yeah! I am using a 2G simcard in it. You need to check if your local telcom provide has kept 2G towers intact. Most are wiping out 2G in US by 2019.
    – Pj_
    May 7 '17 at 20:13
  • so, to answer the OP exists and works...
    – Solar Mike
    May 7 '17 at 20:31
  • @SolarMike Absolutely, many BLE based OBDs won't allow you to do this, but telemetry is the best possible solution, and there are many modules that provide it. Whenever I talk to Fleet operators or Insurance providers, this is exactly what they want.
    – Pj_
    May 7 '17 at 20:34
  • @Pj_ Carlock claims that its device connects to OBD port and is able to send the car alarm to a smartphone through the cloud. Its device works with a sim card. Do you think that they are using 2G sim card?
    – Delmonte
    May 8 '17 at 16:32

As technology stands right now, the answer is "no" or at the very least not make it practical to you. The reason for this is, an ELM327 OBDII adapter uses Bluetooth technology to connect with your phone. A Bluetooth connection is only good to ~100m unobstructed. When you start passing through structures and such, the signal attenuation starts degrading faster. With that in mind, I'm not sure if an OEM car alarm sends any sort of signal through the CANBus, but would bet it sends some sort of signal so as to shut the engine/ignition down so it won't start as well as lighting the lights and honking the horn (or whatever your car alarm does to make you realize it's going off).

On a separate note, there are aftermarket alarms which can pass information through the phone system or paging systems to alert you when there is an intrusion. I don't know how well they work, but do know there is a capability out there which can do this. A friend of mine a few years back had one in his car which he had a remote which would communicate through comms lines (cell phone signal) which he was alerted if his car was being broken into and which he could remotely start the car from just about anywhere he could get a cell phone signal. I wouldn't have used it, but it's out there.

  • The ELM327 is an interface for OBD & CAN; and is not tied to any particular access protocol. While we usually see it in the Bluetooth configuration, it is also available in RS232, USB, WiFi, and GSM
    – Mad Myche
    Oct 18 '17 at 0:28
  • @MadMyche - Thanks for the update. I've only seen them in the Bluetooth version, but it makes sense it might come in other versions. Oct 18 '17 at 0:38

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