MG1 2017 BMW 430i Grand Coupe no communication

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.

I pulled a few identifiers from the file. I’ve also attached the original flash file after it bricked.


Hardware (HWE):

• Hardware_DME8R1_SP11

Hardware Application (HWA):

• DME8.4.x_B48_V1

Bootloader (BTLD):

• MDG1G_LK-CB_011_253.5_3.2
• MG1CS003_LK

Where do I get the stock flash?

antwas said:

¿Dónde puedo conseguir el firmware original?

Click to expand...

I can help you if you still need it.

Good to have you jump in — that would help. The thread's been quiet since June, so @antwas may or may not still be on it, but the info would still be useful for anyone landing here with the same MG1 brick.

If you do have a source, the key is matching what he posted from the dump:

• BTLD: MDG1G_LK-CB_011_253.5_3.2 / MG1CS003_LK
• HWE: Hardware_DME8R1_SP11
• HWA: DME8.4.x_B48_V1

For a no-comms recovery it has to be a full 8 MB internal flash image with boot/RSA area intact, not just the application and calibration blocks — a program-area-only restore is exactly what leaves an MG1 alive on bench but silent on the vehicle CAN bus. That said, the attachment he uploaded here never came through readable on my end, so I can't confirm what state his file is actually in.

If you post the identifiers of whatever donor file you have, we can at least see whether the BTLD revision lines up before he writes anything.