06. Special mode blinker buttons

6. Special Mode / Blinker Buttons

Some firmware disables SWD during normal boot. On supported X3-family VCUs, holding the turn indicator buttons while powering the VCU can enter a service mode where SWD is available.

Use this with connection mode:

[A] Default / Blinker buttons

Basic Flow

1. Connect ST-LINK wiring for normal SWD.
2. Hold the turn indicator buttons.
3. Power the VCU.
4. Keep the connection stable.
5. Run a full 128 KB dump first.

If this does not connect, try mode B or C depending on your ST-LINK adapter.

Notes

This mode is useful because it avoids manual C45 reset timing, but it only works when the service-mode trick is available and the wiring is good.