Composants haute tension endommagés par un accident

An impact has damaged part of the high-voltage system — a cable, a connector, the battery enclosure, or the mountings holding any of them.

This cause behaves differently from everything else in the corpus, because the right response to it is often to stop rather than to diagnose. Elsewhere a fault is something to investigate. Here the vehicle may be reporting that the barrier between several hundred volts and everything a person can touch is no longer intact.

The vehicle's own response is the thing to trust. Electrified cars open their contactors on a significant impact, deliberately and automatically, and refuse to re-energise until the system has been checked. A car that will not power up after a collision is usually behaving correctly, and getting it moving again is not the objective.

Two properties make it dangerous in ways an ordinary collision is not. A damaged pack can be at risk of thermal runaway hours or days later rather than at the moment of impact, which is why recovery guidance for electric vehicles involves quarantine distances and re-inspection rather than a tow and a shrug. And the damage that matters is often invisible — an underfloor pack struck by road debris, a jacking point used wrongly, a cable crushed where a subframe moved a few millimetres.

So the practical rule for an owner is short: after any impact near the battery or the orange cabling, do not investigate it, do not attempt to move the vehicle under its own power, and say a high-voltage fault is stored when calling for recovery. It changes how the vehicle must be handled and who may handle it.

For a workshop the cause is real and repairable, but it belongs to someone with high-voltage training, an insulation tester and the manufacturer's post-collision procedure — which typically requires inspection of the pack enclosure and an isolation measurement before the system may be re-energised at all.