OK so now I can see the full picture. This is a
BMW G90 M5 (hybrid/PHEV) and the issue is the
pyrotechnic battery disconnect (pyro fuse / BST - Battery Safety Terminal) on the high-voltage battery.
From your photos I can see:
- The pyro switch has been fired/triggered during the crash — this is the orange "Contains Pyrotechnic" unit (BMW part visible: 908-206-001 / 8 845 015 03)
- You have a new replacement pyro switch ready to install (the one still in packaging)
- The high-voltage battery is exposed from underneath with the orange HV cabling visible
Here's your situation:
The
B7F02E BAT-HAD: Shutdown Due To Crash Detection fault is triggered because the ACSM fired the pyrotechnic battery disconnect during the crash. This physically cuts the HV circuit as a safety measure. Until this is resolved, the car will NOT start.
What you need to do:
1. Replace the fired pyro switch — which you already have the new part for. Install it on the HV battery. Make sure the connector (black plug with green/white wire) seats properly.
2. Replace or reset the ACSM — the crash event is stored in the ACSM. Even after replacing the pyro fuse, the ACSM still holds the crash flag. You need either:
- A new virgin ACSM, programmed and coded to the car via ISTA+
- OR the existing ACSM reset (crash data cleared from EEPROM) — some specialists can do this on bench
3. Clear crash data from BDC — the Body Domain Controller also stores the crash telegram on G-series. Use ISTA+ service function "Delete crash-relevant entries."
4. Clear all DTCs system-wide after everything is physically repaired and modules replaced.
Important note on the HV system:
Since this is a high-voltage hybrid system, after installing the new pyro switch:
- The SME (battery management module) may also need to have its crash flag cleared
- The EME (electric motor electronics) may store related faults
- You may need to perform an "HV system activation" procedure via ISTA+ after reassembly
Bottom line: Replacing the pyro fuse alone won't fix it. The ACSM crash flag is what's holding the start inhibit. Pyro switch + ACSM reset/replacement + BDC/SME crash data clear = car will start again.
What tool do you have available — ISTA+, E-Sys, or something else? And has the ACSM been addressed yet?