Finding
Full OTA stays rare because most vehicles run dozens of supplier ECUs that cannot be updated remotely, and fixing that means redesigning the E/E architecture
Full OTA means updating every major domain - powertrain, battery management, charging, driver assistance, body and infotainment - remotely, with rollback and audit. Tesla resolved 98% of its 2025 recalls that way; across the US industry only about 15-16% of recalled vehicles in late 2025 could be fixed over the air. The reason is architecture: a conventional vehicle runs 40-150 ECUs from many suppliers, each with its own software, update method and validation rules.
Making full OTA standard requires central compute with zonal controllers, enough flash memory for A/B partitions in every updatable controller, a secure network to reach them, in-house ownership of the software, and validation processes that can approve safety-relevant changes quickly. That is a platform redesign, which is why it arrives with new architectures - Rivian's Gen 2, VW's Rivian-based platform, GM's and Ford's next-generation EV electrical systems - rather than as a software patch.
Barriers
Barriers to full OTA
| Barrier | Why it blocks OTA | Fix |
|---|---|---|
| Supplier ECUs | Software owned and validated by suppliers | In-house software; fewer ECUs |
| Legacy E/E | Slow CAN links, no path to many controllers | Ethernet backbone, zones |
| Memory | No room for A/B partitions | More flash per controller |
| Validation | Safety changes need re-certification evidence | Simulation, staged rollout |
| Cost and incentives | Dealer service revenue; per-model engineering | Platform-wide software ownership |
Sources
Sources and scope
- Scope
- Why Full OTA Updates Are Still Rare
- Sources
- BizzyCar recall reports (2024-25); NHTSA; Tesla; Rivian
- Updated
- October 2026