Freematics Forum

Hi Stanley,

I have an old car (Opel Vectra B 1998) which is possibly in ISO 9141 and I bought the I2C Adapter for Arduino. Is there a way to implement this protocol ?
If yes, how can I do it ?
To illustrate, how did you implement the other protocols ?

Thanks you,
Coco24

Have you uploaded all of the latest code to your arduino? I believe Stanley made a few updates that helps connect to older protocols. By default, the ELM327 chip (the OBD2 chip in the freematics unit) is told to auto select a protocol. It does look like 9141 is supported. I've had trouble on older cars where I have to start the car, plug in the unit, unplug the unit, then plug it back in. I've also had to put in some time delays here and there to let the older ECU catch up to the freematics' calls.

Hi,

The problem with my car is that when the car was made, the ISO 9141 was not under an offical legislation for all manufacturers. So maybe Opel has made a custom implementation of the ISO (like modifiying the handshake or init sequence).

For example, a common and cheap OBD Reader (which is logically designed to support all protocols including ISO 9141) was unable te connect to my car, whereas a dedicated Opel tool (OP-COM) is able to connect to my car with no difficulties.

Unfortunatly, the OP-COM is only designed to work with a proprietary software (computer required).

I'll try as soon as possible the latest code to be sure.

On which car have you already tried ?

Mostly bmws and subarus. The oldest was a 99 3 series. You might want to google around for others that have gotten the opel working with the ELM327. It's likely just figuring out what the best init commands are.

It's not very easy to find something useful, all the documents I've found are in english (not my native language) and there is no custom init sequence for the Opel specific protocol. I've tried to ask to Opel but they replied to me that the protocol is their property (of course). I only know my car has a K-Line connection (so ISO-9141 OR KWP-2000).

I'm trying to search a little more on this

Have you tried manually setting the protocol? By default it's 0 which says "auto select" but on my subaru, I had success manually selecting the right protocol (4 I think?).

Yes, unsuccessfully, but I remember the device does not work with 2 other cars : Insignia 2009 and Cooper S 2010, auto or manual protocol.
A cheap OBD reader can connect with both and display live data.

I think there is something wrong with my code (or with the adapter, I don't know)

Yea it should definitely work on those other cars.

Hi,

After a new try with the new librarie on my father's Opel Insignia (2009), the adapter work quite well with a CANBus protocol (obviously) but doesn't work on a Mini Cooper S (2010) even if I set manually the protocol. I don't know why...

I did not have the time to try the new librarie with my old Vectra