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What to do if…
your electric vehicle displays a high-voltage or battery system warning and you don’t know what it implies

Short answer

Treat it as a safety warning: slow down, pull over somewhere safe, stop the vehicle, and don’t continue driving until you’ve checked the message severity and arranged help if it’s red/“stop”/power is limited.

Do not do these things

  • Don’t keep driving “to see if it clears” if the warning is red, says stop/pull over, or the car limits power.
  • Don’t keep cycling the power on and off trying to clear the warning; stop safely first and follow the on-screen instruction and roadside advice.
  • Don’t touch, open, or cut anything labelled high-voltage, and don’t go near orange cables or damaged wiring.
  • Don’t plug in to charge if the warning suggests a battery/high-voltage fault, or if you notice smell/heat/smoke/hissing.
  • Don’t park in an enclosed garage or tightly next to other vehicles if you suspect a battery problem (heat/smell/smoke or escalating warnings).
  • Don’t allow recovery that drags the car with driven wheels on the ground unless your handbook explicitly permits it.

What to do now

  1. Make a safer pause first. Indicate, reduce speed smoothly, and pull over to the safest available place.
  2. If you’re on a motorway or high-speed road, use the right safety rule for where you stop:
    • If you’re stopped in a live lane (or it’s not safe to get out): keep your seatbelt on, hazards on, and call 999 and ask for the police (or use your in-car SOS button if you have one).
    • If you can get to a safer place (hard shoulder or an emergency area): stop there. If it’s safe to exit, get out via the left side, move behind a barrier/away from traffic, and call for help.
  3. Secure the car. Put it in Park, apply the parking brake, switch on hazard lights, and switch the vehicle fully off.
  4. Do a quick “risk check” from a distance (no troubleshooting). Look and listen for smoke/steam/vapour, popping/hissing, unusual heat, burning smell, leaking fluids, or visible damage/exposed cabling.
  5. If you see/hear any danger signs (or fire): move well away, keep others back, and call 999. Say it’s an electric vehicle and you have a battery/high-voltage warning.
  6. If there are no immediate danger signs: read the exact on-screen wording/colour. Treat red, “Stop safely now”, “Pull over”, “High-voltage fault”, or “Limited power” as do-not-continue unless the manufacturer/breakdown provider explicitly tells you it’s safe to reposition.
  7. Call for EV-appropriate help. Call your manufacturer roadside assistance or breakdown provider. Tell them:
    • the exact warning text/colour,
    • your location (and if you’re on a motorway/live lane/emergency area),
    • whether there’s any smell/heat/smoke/hissing,
    • whether charging was involved (e.g., it appeared during rapid charging).
  8. Capture key details (30 seconds). Photo of the warning message, time, and what you were doing (driving/charging). This helps diagnosis without guesswork.
  9. Until you’re told it’s safe: don’t charge it, don’t move it unnecessarily, and keep people clear of the vehicle.

What can wait

  • You do not need to work out the technical cause right now.
  • You do not need to decide whether it’s the traction battery or the 12V system at the roadside.
  • You do not need to organise repairs now—focus on safe stop + safe recovery.

Important reassurance

EV warnings can be triggered by issues that are fixable, but it’s safest to assume any high-voltage/battery-system warning could affect safety until a professional confirms otherwise. Stopping and getting help is the right move.

Scope note

This is first-steps-only guidance for the moment you see the warning. Next steps depend on the exact message and what roadside assistance advises.

Important note

This is general safety information, not mechanical or legal advice. If the vehicle instructs you to stop, or you notice heat/smoke/hissing/odours, treat it as urgent and involve emergency services and professional roadside recovery.

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