My interface is finally completed, I rewired it with 28AWG instead of 22 (what I had around), it's nicer
On my bench I tested the output of the ISO line of the MC33290 with a scope when I send the 0x33 and it's ok. I am wondering if the 2 grounds in the car are connected or not (pin 1 and 2 of the OBD2 connector). I will do a test with the MC ground on pin 1.
Else I will take an inverter and a scope in the car to test signals.