OBD II Capacity?

I am beginning to play with the OBD II module. One of the things I am thinking about building is a device which measures the time that it takes to go from 0 to 60 mph. I am concerned about the load that can be placed on the OBD II network.

I have done some searching, but aside from references to use of the car’s network for diagnostic purposes, I have I have not been able to determine if it is used for operational purposes. I am concerned that if I poll the network too often, I might impact some operational component of the car, like the engine, and cause a reboot or worse.

Does anyone have any knowledge of OBD II networking?

You’re probably going to be fine. I know lots of people who use OBD to get real time engine data for tuning purposes. The ECU hardware sends its info back to the OBD, so you shouldn’t have to worry about screwing anything up.

I have no knowledge, but am waiting to hear in anticipation of how you go :slight_smile:

Typically though, I thought leveraging the OBD data was a “read” process where you didn’t need to poll a sensor to get data, things like the RPM sensor spat out data periodically and the tacho simply filtered for those messages and only got those off the network, and reacted accordingly.

I think you might be right! There is a mode for continuous measurements.

I have to go back and check the driver source.

I’m starting to play with it myself (thus my question about hex codes).

FWIW - my 2006 Mistubishi reports all kinds of data, my 2007 Ford crossover not so much. The PID A1 00 is supposed to return the a listing of what codes 00-20 that are supported by that vehicle …my Ford doesn’t even respond to that, not even all 0s. Using the GHI driver (doing some research to see what else can be used), my Ford doesn’t report throttle position, current speed or RPM.

So, pardon the pun, your mileage may vary with OBD.

I plan experimenting on my co-worker’s vehicles in the coming weeks seeing what type of cars report what data :slight_smile:

@ mhectorgato -

i will be testing on a 2008 car, so I suspect it will have plenty of pids. it is not an American car. :slight_smile: