We are building a mobile application for vehicle diagnostics. We are using the ELM327 OBD-II tool for fetching the data from the car using Nodejs. The application is being built and we are facing some issue regarding certain parameters of the car. We have used and tested OBD-II in various cars and we are not getting the values of fuel level input and Vehicle Identification Number of a particular car. When we tested, we got no data as the result. How to resolve them? Any other method to get these data?

We also want to know that in any case, it is possible to detect an accident, Tow alert detection, Level of Car using Air pressure in tyres with the help of the ELM327 OBD-II.

Is there any way to control ignition on/off through OBD-II?

If you know anything related to this, Please revert back.

Thanks in advance!

  • Lots of questions with answers about this topic on here, have a search...
    – Solar Mike
    Aug 7, 2018 at 14:44

1 Answer 1


I believe OBD II is an international standard but that not all functions are uniformly supported by all models so some things may not be available. I have no idea about the generic interface but I can tell you that on Volkswagen group cars it is possible to interrogate the air-bag module via the OBD II port and that will give you a good indication if the vehicle believes it has been in a serious collision.

I believe that on many vehicles, the ignition has to be switched on to make the OBD II port live so tow alert detection may be difficult as would switching the ignition on and off remotely. Using air pressure sensors would only be possible with cars fitted with a TPMS and I suspect even then you'd struggle as certain vehicles such as the BMW system use differences in rotational speed between wheels to establish tyre pressure drops. That said, you could potentially use a feed from wheel speed sensors to detect a two wheel tow.

  • Air Bag Module, We'll look into it for particular car of Volkswagen. It is not necessary to switch ignition on to transfer the data from car to obd. We can use the inbuilt battery in obd so that communication remains unchanged. I don't know that how to control the ignition using the OBD-II. Do you have any answer related to that? Fuel Level Input and Vehicle Identification Number, Anything which could be of help Aug 8, 2018 at 6:23

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .