Didier,

you may need to send a periodic "tester present" signal after entering the diagnostic session via "10 03".

Depending on the vehicle, the diag session automatically terminates within 60 seconds or less, if the tester presence isn't signalled.

The RE toolkit contains a tester presence tool:

OVMS# re obdii tester ?
Usage: re obdii tester list|start|stop|stopall
list                 List current tester present signals
start                Start sending a tester present signal to an ECU
stop                 Stop tester present for an ECU
stopall              Stop tester present for all ECUs

This normally isn't needed if you send the commands directly in series.

If you can exclude that issue, I'd say you've got an error in the key calculation.

Regards,
Michael

Am 28.09.24 um 22:54 schrieb didier--- via OvmsDev:

Hi,

I need to put a ECU into diag mode and access private data in a secured session.

I am supposed to send "10 03", then "27 03", receive a seed, and send the private key with "27 04".
This is working fine with the terminal in CarScanner mobile app connected to a BT dongle, but when I try to use the OVMS box, the "10 03" is ok, but "27 03" return a
serviceNotSupportedInActiveSession
error. It is possible to start a secured / private session with the OVMS box ?
Didier
_______________________________________________
OvmsDev mailing list
OvmsDev@lists.openvehicles.com
http://lists.openvehicles.com/mailman/listinfo/ovmsdev

-- 
Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal
Fon 02333 / 833 5735 * Handy 0176 / 206 989 26