Is starter interrupt /disable /kill possible for Hybrid or EV cars?

The terms Starter Interrupt, Starter Kill, KillSwitch and Starter Disable all refer to immobilizing a vehicle or preventing it from starting by interrupting the starter, done in the past by using a hidden switch. It was meant as an attempt to prevent theft of vehicles left on the street overnight or far from the owner's sight. In mid-2000, after cellular services became more affordable, new electronic devices started to replace the simple switch. And not only that, but those devices were transmitting the current vehicle location back to the owner. Named GPS trackers, those devices are capable of executing commands sent to them remotely. Arguably the most useful command one can send to a car is Starter Disable, which can prevent not only theft, but also misuse or unauthorized use of the vehicle. This is a necessary option for every car rental business, financial institutions or other businesses in the car financing or recovery. That includes car dealers and repossession companies. And it even helps to prevent the family car being operated by kids under influence. 

Now let's go back to the term itself, and why exactly Starter Disable or StarterKill?

It's against the Law in US and Canada to shut off a vehicle in motion with a user-installed device, due to potential safety hazards. 

Just imagine driving down the highway at 60-70 MPH, when suddenly your engine stalls. Not only your car will sharply decelerate, but you will also lose the power steering, maybe even the brakes. The chances of a multi-car accident and a pile-up are significant. Every single person involved in the accident has 3 years to take you to court for causing the accident. And with so many law offices specializing in “injuries”, as well as advertising it, chances are you will meet them in court. Those responsible for the installation of the device, which caused the engine to stall, will be first in line liable for the accident.

Perhaps now you understand why these devices are designed to interrupt only the starter, in order to avoid liabilities. It's safe to disable this component of the engine, that is not involved in the vehicle operation at any other time, except the engine start. At the time your engine starter is cranking (or it's being disabled), your vehicle is stationary, and that can't cause liability issues.

After all that said,it's time to move on to the hybrid powertrain. 

The first problem with it is the absence of a conventional starter. Instead, the engine is turned over by an electric motor, which also serves as a torque booster. It can also move the car without the engine running at all.

Some Mild Hybrid powertrains implement both a conventional starter motor and an additional 48V electric motor, as a part of the transmission. Interrupting the conventional starter will not prevent the ar from starting, as the electric motor in the transmission will take over this function.

The 48V electric motor is designed t run at much higher currents and voltages than a conventional starter motor. It is also electronically switched and managed, unlike the simple relay of the conventional starter. It is not possible to safely interrupt the 48V, high current electric motor.

And this is what the problem is when trying to do a starter interrupt on an engine with no starter in it, or one that has a dual starting system. It is not uncommon to see hybrid powertrains in many newer model cars, like Mercedes AMG, Audi and BMW. Land Rover/ Range Rover are not far behind. And, of course, Toyota, Honda, Ford and Hyundai have them for over a decade now. 

So how to prevent the start on one of these? There are a few safe ways to achieve that, which does not include cutting the brake light switch, as many do. Disabling the brake lights is illegal! Brake lights are a safety feature, and it's against the law for any safety feature in a vehicle to be tampered with or modified. In case of an accident, the installer of this device will be liable.

The safe way to disable the start in a hybrid vehicle is to use our Startblocker smart relays and modules, and follow the installation instructions closely. This can not only save the installers a lot of headaches, but also time. It will also give confidence to your customers and make them come back and spread the word.

Training for working on hybrid vehicles and EV is available here:

If you need installation service on a hybrid vehicle and want it done safely and securely, click here.

Not sure if your car is a hybrid? This short post will help you easily determine.