How to record data with a laptop ?

My automobile has a separate inboard computer that handles suspension, traction, speed sensors, body gadgets...

Reading error codes can be done only at the dealer shop, 140 miles away, for an obscene sum. And not willing to risk driving with an unknown diagnostic pending. It is not about engine error codes readable with a OBD2 scanner (which I have)

From information gathered, the data is available/presented at a single pin on a connector.

Is there a way by connecting such data pin to a certain pin of the serial port, and with some command; bring that line briefly down or up (or something else) to initiate the spitting of data, and recording it in the hard drive, to attempt interpretation later ?
Data speed/format is unknown. Recording a string of ones and zeroes for a few seconds -if that much- could bring me closer to the task, to try to read with some simple edit? program, or whatever you suggest.
Protocol is probably ISO-14230 ; or CANBUS ISO15765-4; or ISO 9141-2

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Without the data format and speed you'll be fighting an uphill battle.

Start here:



As you can see, there are 2 (two) CAN data speeds lines (low and high). And one of the others should be the data control line.

You'll need find the data format. That should be universal for OBD2, but I don't know about brand specific formats not covered by standard OBD2 protocals.

Using a standard terminal emulator app (used to be one under Windows, but not so anymore) you could at least capture the data stream via a serial port on the lap top, but interpreting the data would be a nightmare.

You'd have to find the specific query commands (and structure) to get at the data you listed (suspension, sensors, etc.).

A worthy venture, but a blind shot in the dark might end up being very frustrating.

To be honest, if it were me (and I realize it's not) I'd hit the sites that deal specifically with your vehicle.

some codes are free/open (mandatory) like engine codes etc. you can find info for those easily online or from publications (automotive associations etc.). those essential codes are readable by various ODB2 scanners. if you have a working scanner, you should already have a way to query anything (supported or not), it's just that your scanner will not be able to interpret/decode unsupported replies. this is onbvious because there are many more codes which are not public (for example controlling mirrors, seats etc.). when ever we did work on a project that talks to ECUs, there was a non-disclosure agreement to be signed before the documentation on those secret codes is handed over (always needed in order to make test equipment for automotive production lines).

Its a while back however nerd kits did something like this, converted obd into rs232 and displayed the results in visual basic, probably not what you want but a start.
I'm not an expert but I thought there are different standards with obd, pulse width, serial, ppm etc.