You have to separate the hardware from software. When you said "unable to contact the ECM", that is purely software issue since your phone doesn't speak same language as ECU. Hardware is connected properly.According to the Chinese manufacturer's statements in the OBD2 devices that I bought there is a protocol 9141-2, and they both didn't work, the two devices ware unable to contact the ECM!
ok, we need to back up and learn what ISO-9141-2 standard is...Yes is purely software issue.
& No. phone doesn't speak with the ECM. The speak with the ECM is performed only between the Chinese device and the ECM, and the Chinese device transmits decoded data to the mobile.
The ECM reading software is burned into the Chinese device (protocol ISO-9141-2). Bluetooth communication to mobile, it also has some standards, and with this Bluetooth communication there was no problem. In the Chinese device, according to the manufacturer's specifications, the protocol you mentioned (ISO-9141-2) is burned in to it.
LINK to aliexpress
View attachment 45483