If your Tesla unexpectedly loses power while driving, the first thing to understand is that the car has safety features built-in to help bring it to a stop safely. Modern Teslas have regenerative braking, meaning when you lift off the accelerator, the electric motor becomes a generator and slows the car down. So if power is lost, regenerative braking will still function to slow the vehicle.
What causes a Tesla to lose power while driving?
There are a few potential causes for a Tesla to lose power while driving:
- Battery runs out of charge – Teslas have an EPA-rated range when fully charged. If you drive beyond that range, the battery will deplete and the car will lose power.
- Software failure/crash – The car’s software may experience a crash or failure, resulting in a power loss.
- Physical connection/wiring issue – A problem with physical wiring connections could lead to power loss.
- Component failure – Failure of an important component like the battery, motor, or inverter could cause power loss.
Running out of battery charge is by far the most common reason. Teslas display the estimated remaining mileage/range on the dashboard screen, so you should have warning that the battery is depleting. The other issues are less common but can occur in any complex electronic system like a modern car.
What happens when a Tesla loses power at speed?
If a Tesla loses propulsion power at highway speeds, here is a look at what would happen:
- Regenerative braking engages – This will slow the car down as if you were applying gentle brake pressure.
- Hazard lights turn on – The emergency flashers will activate to warn other drivers.
- Power steering and brakes remain operational – You can still steer and stop the vehicle, just with more effort.
- Car coasts to a halt – The car will coast to a stop once regenerative braking has slowed it as much as possible.
- Brake manually if needed – The friction brakes can be applied manually if more stopping force is needed.
The car will not simply shut off and lose control. You as the driver just need to steer it to the shoulder and brake as needed to come to a complete stop.
What happens if power is lost at lower speeds?
If driving at lower speeds like in a city or neighborhood, power loss is less critical. Here is what would occur:
- Regen braking engages to slow the car.
- Hazard lights come on.
- Coasting speed is lower due to lower initial speed.
- Can brake manually to a full stop if needed.
With the lower speeds, you have more time to react and bring the vehicle to a safe stop using the manual friction brakes.
Can you steer without power assist?
Yes, you can still steer a Tesla that has lost power, it just takes more effort. Tesla’s electronic power steering system is powered by the main battery pack. So when the battery is depleted, it disables the power assist. But the steering system has a mechanical connection to the wheels, so you can still turn the wheels manually – it will just require more strength.
What about braking without power?
You can still brake a powerless Tesla. The braking system is fully hydraulic and mechanically actuated, so it does not require battery power to function. However, you lose the regenerative braking that slows the car first in a power loss scenario. The friction brakes will stop the car on their own, you just have to press the brake pedal harder than usual.
Should you put the car in neutral if power is lost?
Tesla actually recommends keeping the car in gear when coasting to a stop without power. Here’s why:
- Keeping it in gear allows regenerative braking to work – this provides maximum deceleration.
- Being in gear gives you better control of the car’s speed.
- Less risk of accidentally shifting to the wrong gear.
The car will automatically shift to neutral once it comes to a complete stop. Until then, it’s best to keep it in gear to use regenerative braking and have better control.
Can you restart the car after a power loss?
Once you’ve brought the Tesla safely to a stop, you may be able to restart it, depending on the cause of the initial power loss:
- Battery ran out of charge – The car cannot be restarted until it is charged or receives enough charge via towing/pushing to turn back on.
- Software crash – A restart may resolve a software problem and restore power.
- Physical wiring issue – Repair of the wiring may be required before restarting.
- Component failure – Replacing the failed component such as the battery, inverter, or motor is needed before restarting.
So for a battery charge issue, recharging is required. For other causes, restarting the car after a repair may be possible to get it going again.
What are the steps to take after power loss?
Here is a summary of the steps to take if your Tesla loses power while driving:
- Remain calm and keep holding the steering wheel.
- Press the hazards button to turn on flashers.
- Coast to a stop using regen braking and manual friction brakes.
- Pull over to a safe location off the road.
- Shift to Park once at a complete stop.
- Contact Tesla roadside assistance for help.
- Determine if car can be restarted once stopped.
- Have the car towed to a service center if restart not possible.
Following these steps helps maintain safety and get help to resolve the power loss issue.
Does Tesla provide roadside assistance?
Yes, Tesla provides 24/7 roadside assistance with their vehicles. If you have a power loss or any issue that leaves you stranded, you can contact Tesla roadside assistance for help. Here are some of the services they can provide:
- Towing – They will dispatch a tow truck to transport your Tesla to the nearest service center.
- Mobile tire service – Flat tire replacement service can be dispatched to your location.
- Battery jump-starts – Mobile technicians can jump-start a fully depleted battery.
- Lockout service – Assistance with key fob or mobile app issues locking/unlocking the vehicle.
Tesla’s roadside assistance number is 1-877-79TESLA. They should be your first call after getting to a safe location if your car loses power on the road.
Is it safe to drive again after power loss?
After a power loss event, the car should not be driven again until the root cause is properly inspected and repaired if necessary. Here are some guidelines on when it is safe to drive the Tesla again:
- Battery depletion – Safe to drive once sufficiently recharged.
- Software crash – Safe after technicians verify and restore proper software operation.
- Physical wiring issue – Safe after wiring repair and system verification.
- Component failure – Safe only after failed parts replaced and testing.
Never attempt to drive the car again after a loss of power until Tesla service technicians can properly diagnose and correct the failure. Driving with an underlying issue risks much greater problems, damage, or another unexpected power loss.
How can you prevent power loss while driving?
While a power loss can never be fully prevented given the complexity of modern vehicles, there are things Tesla owners can do to minimize the risk:
- Keep the battery charged – Monitor your charge level and range.
- Address alerts and warnings – Resolve any battery or system alerts that appear.
- Have yearly servicing – Routine maintenance helps detect issues.
- Watch for software updates – Install the latest firmware updates.
- Inspect connections – Check for any loose wiring under the hood before driving.
- Consider range on trips – Carefully monitor vehicle range vs. trip length.
Being diligent about battery charging, vehicle maintenance, and monitoring driver alerts can help avoid many common causes of unexpected power loss.
Conclusion
Power loss in a Tesla or any EV can be alarming but regenerative braking, hazard lights, and manual friction brakes enable bringing the car to a safe stop. Remaining calm, contacting Tesla’s roadside assistance for help, and refraining from driving again until the issue is diagnosed are important to ensuring safety. Preventative steps like charging diligently, installing software updates, and having yearly servicing can reduce the risk of a power loss occurring in the first place.
