BMW PHEV: Safety fuse replacement is extremely expensive

Original Article ↗ Hacker News Discussion ↗

EV vs PHEV vs ICE Complexity

  • Many argue EV powertrains are intrinsically simpler than ICE (fewer moving parts, no turbos/valve tricks, regenerative braking), but modern EVs are still “computers on wheels” because of how they’re designed and regulated.
  • PHEVs are widely seen as worst-case complexity: often combining full ICE + full EV systems, though some designs (e.g. Toyota e-CVT) are relatively elegant while others (VW DSG-based PHEVs, Ford hybrids) are nightmares.
  • Several point out that modern ICE cars already have multiple CAN buses, complex emissions systems (DPF, EGR, evap, etc.), and heavy software – so this issue is “modern car” rather than “EV” specific.

BMW’s Design and Repair Costs

  • The thread treats this case as primarily a BMW / German premium-brand problem, not an inherent EV issue.
  • Complaints focus on: generic parts embedded in welded, non-serviceable modules; cryptographically locked controllers; VIN-locked components; and a fragile, multi-step ISTA process that can “brick” packs and force replacing good battery modules.
  • €4k+ for a fused battery-control module is seen as user- and environment-hostile, effectively totaling cars for minor incidents and crushing resale values.
  • Some defend BMW as designing around liability and safety; others see deliberate cost-extraction and lease-focused engineering (“Ultimate Leasing Machine”).

Safety, Pyrofuses, and High Voltage

  • There’s agreement that HV batteries pose qualitatively different risks than fuel tanks: punctures or shorts can be immediately lethal, so crash fuses and interlocks are justified.
  • The core dispute is how far you need to go:
    • One side: full re-certification after any crash is prudent; opening packs is dangerous; manufacturers would be sued for any post-repair electrocution or fire.
    • Other side: competitors (Tesla, VW, GM) manage cheaper, more targeted pyrofuse replacement and resets; BMW’s process adds unnecessary cost, complexity, and failure modes without clear safety benefit.

Right-to-Repair, DRM, and Lock-In

  • Many connect this to broader “DRM in cars”: VIN-locked parts, proprietary tools, subscription features (heated seats), and software gating of even OEM replacements.
  • Examples from BMW, VW, Lamborghini, Ferrari and others show crash codes and BMS locks that independent shops struggle to clear, sometimes forcing purchase of entire packs.
  • Commenters call for stronger right-to-repair laws, standardized diagnostics, and design-for-repair requirements, arguing current practice increases waste, insurance costs, and CO₂ footprint of scrapped vehicles.

Brand and Design Contrasts

  • Tesla is frequently cited as comparatively repairable: cheap pyrofuse parts, accessible pack “penthouse” on newer models, excellent free service manuals and service mode; but others note Tesla also has inaccessible components and its own crash lockouts.
  • Toyota (Prius/RAV4 PHEV) and Mazda are praised for robust, relatively simple hybrids and thoughtful serviceability; Dacia and older Japanese cars for low-cost longevity.
  • German brands (BMW, VW, Mercedes, Audi) are repeatedly described as over-engineered, fragile outside narrow conditions, and ruinously expensive to repair after warranties or leases end.

Policy, Environment, and “Peak Car”

  • Some blame EU climate and cybersecurity regulations for pushing electrification and cryptographic locking; others say the “EU engineering” angle in the article is mostly clickbait.
  • Several lament that CO₂ accounting ignores the emissions from early scrappage, wasteful parts replacement, and constant dealer-only service.
  • There’s strong nostalgia for ~2000–2010 “peak car”: analog controls, OBD-II but few screens, simpler electronics, and cars that could be owner-maintained for decades.