We published an article on restoring an Audi A4 SRS unit (8W0959655J) that developed an unrecoverable internal error B2000-00 after a failed software update.
The challenge was the board’s read-protected Renesas V850E2 processor. To bypass the protection we studied the single-wire UART bootloader protocol and applied voltage glitch technology: an overclocked Raspberry Pi Pico (250 MHz) controlled the CPU flash supply pin (FVDD), injecting microsecond power dips at the right moment.
After a successful glitch attack we dumped both Code-flash and Data-flash. The firmware was restored with our odx.py script, and the EEPROM was sourced from a donor 104-version unit. The internal error cleared and the unit again responds correctly to diagnostics.