Freematics Forum

Having a slight issue with my adapter cable and would like to confirm if it is a code or a cable issue. My setup is currently just an arduino nano and a TTL to RS232 adapter reading the passing RX and TX signals from the cable to the arduino. My adapter connects to the cable using the standard while(!obd.init()) and while doing so the serial console prints SEARCHING... which I would suspect would be the case. If no connection can be established (ie: car is off) the console prints UNABLE TO CONNECT and tries again. Also as I would expect. Now, when a successful connection is established I simply read by if(obd.read(PID_RPM, rpm)) which returns some value which evaluates to true as the program continues and flashes an LED and yet the console just prints NO DATA. The rpm value also does not evaluate to that of the car and yet seemingly reads correctly from the cable. Any ideas? (car is a 1999 VW passat which is using ISO-9141 protocol which is supported by this cable)

What car?

Read the last line of my prior post. Its a 1999 VW Passat. It uses the ISO-9141 protocol so it should work right?

ISO-9141-2 is supported. It's different from ISO-9141.

Thats what this car uses. ISO9141-2 and yet the cable returns >NO DATA after connecting when I read from it. That was my original question.... What else might cause this? Other than having the wrong protocol.

Maybe you can try on a new car to eliminate the possibility of malfunctioning of the adapter.