The symptoms you're describing — stock flash restored via bench but DME still has zero communication on the car — almost always point to an
incomplete flash restore.
Key question: was the full flash restored or only the program/calibration area?
MG1CS003 (B48 in your F36 430i) has multiple flash regions. If the failed BM3 attempt on a locked ECU corrupted the
boot sector or RSA/signature area, and your paid service only restored the application/calibration blocks, the DME may appear fine on bench but won't properly boot and communicate on the vehicle CAN bus.
Why ISTA+ says "replace DME":
That message simply means ISTA+ can't see the DME on the bus at all. It's not a hardware death sentence — it just confirms zero communication.
What to check:
- Ask your flash service exactly which areas were written back. You need a full bench restore (all blocks including boot/RSA), not just application + calibration.
- After the restore, read the DME back with Multiprog and compare checksums against the stock file — do they match across all areas?
- On the car side, check CAN activity on OBD pins 6 & 14 with a scope or CAN sniffer. If the DME is transmitting nothing, it's not fully booting.
Note on ISN:
If the ISN was corrupted during the brick, the car won't
start, but the DME should still communicate on the bus for diagnostics. Since you have
zero communication, ISN is not your primary issue right now — flash integrity is.
Share the
HW and SW numbers from the DME label (or from the Multiprog read info) and confirm which blocks your service restored, and we can narrow it down further.
