Freematics Forum

I mean negative response codes. Not negative values. Services can report that they are not supported, not ready, response pending, etc. The negative response Service is $7F. So for example if a scan tool is requesting say the CVN (Sevice 0x09, InfoType 0x06.) The vehicle could respond something like...

Is it possible to return negative response codes (ISO-1420, CAN) with the stock software/firmware or would we need to modify it?