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None of the keyless start systems do this, on purpose. Because this may lead to very dangerous situations. Imagine your engine shutting off on the highway, and

by LeonM 4y ago

None of the keyless start systems do this, on purpose. Because this may lead to very dangerous situations. Imagine your engine shutting off on the highway, and your steering wheel locks, just because the car briefly looses response from the keyfob... Also, just about every keyless entry systems have a physical backup key, to start and drive the car in case the battery in the keyfob is empty. A periodical re-authentication would make this impossible. Stuck in the middle of the desert with a perfectly good car, but an empty keyfob battery? Well, sucks to be you, you'll likely die, but at least your car won't be vulnerable to relay attacks!

the8472 4y ago
That doesn't mean it's impossible to prevent relay attacks, it's just that people choose not to. Additionally, the highway scenario could also be mitigated with a warning and a grace period. The desert scenario can be mitigated with having a fallback such as having the contactless system double as a smartcard you can put into a reader or by wireless power transfer. Plus, if your contactless system fails in the desert you're screwed anyway as soon as you turn off the engine once.