BMW, Toyota, How to get temperature from external sensor, OBD

[pwok]

Hello,
I'm looking for informations about OBDII. I know how to read from ECU RPM's, Speed, trough the OBD port using ELM327, but I would like to get other information. Is it possible without professional diagnostic interface? I mean external temperature sensor which is under the front bumper. Climatronic uses this information, and I want too.

Thank you for great forum.

 

[BradtheRad]

If you want to do it without the diagnostic interface...You will need to get at the wires coming from the sensor. You must either cut the sensor's wires, or attach a Y-connector.

If it is an ordinary analog sensor, then you can feed its signal to a circuit which responds in a linear manner, putting out a voltage which can be read on a meter.

As you know, there is a risk of ruining something in the vehicle's existing circuitry. You may not be able to put it back the way it was. Therefore it might be safer to install your own temperature sensor. You can calibrate it to the vehicle's temperature reading.

 

[pwok]

Thank you for reply.

I have to connect via OBD port, unfortunately. It means that ELM327 cannot read nothing except Engine Parameters.