An auto start kit lets you start your car remotely using a key fob, smartphone app, or button in your home

An auto start kit is an aftermarket system that sends a wireless signal to your vehicle's engine, turning it on from a distance. You don't need to be in the car or even near it. The most common versions use a key fob with a dedicated button, though newer systems let you start the engine through a mobile app on your phone. The kit sits between your ignition system and battery, intercepting the signal that normally comes from your key being turned in the ignition.

The main reason people install these is comfort: you can warm up the car on a cold morning before you step outside, or cool it down in summer heat while you're still in your house or office. Some systems also include security features like geofencing, which automatically locks the doors or sends you an alert if the car moves without your phone nearby. The installation is usually done by a car alarm shop or dealership, not by you at home.

Key Takeaways

  • Auto start kits use a wireless signal to turn on your engine from outside the vehicle, typically through a key fob or smartphone app.
  • Installation costs range widely depending on your vehicle make and model, from around $300 to $1,500 at a professional shop.
  • Most systems require your car to be in Park with the brake pedal released, and they shut off automatically after 10 to 20 minutes if you don't drive.
  • Some insurance companies offer small discounts for remote start systems because they can reduce theft, though you should confirm this with your provider.
  • Factory-installed remote start (offered by the automaker) is usually more reliable than aftermarket kits but costs more upfront.

How the wireless signal reaches your engine

When you press the remote start button, the key fob sends an encrypted radio signal to a receiver module installed in your vehicle. That receiver talks to the car's computer and tells it to crank the engine without requiring the key to be in the ignition. The system includes safety locks: the engine won't start if the car is already running, if the door is open, or if the brake pedal is pressed. These prevent accidental starts and protect against someone else starting your car without permission.

The receiver module is wired into your ignition system, starter motor, and sometimes your alarm system. A professional installer runs these wires through the dashboard and under the steering column, which is why installation takes several hours. The kit also includes a relay box that handles the electrical switching, because the small signal from the fob isn't powerful enough to turn the starter motor on its own.

Aftermarket kits versus factory-installed systems

Aftermarket kits are sold by companies like Viper, Compustar, and Avital and can be installed on most vehicles made in the last 20 years. They're cheaper upfront than factory options and offer more features—many include two-way communication, so the fob vibrates to confirm the engine started. The downside is that installation quality depends on the shop doing the work, and some kits don't integrate as smoothly with your car's computer as a factory system would.

Factory remote start comes built into the car when you buy it or can be ordered as an add-on from the dealership. It's engineered specifically for your vehicle's electrical system, so there's less risk of conflicts with other features. However, factory systems cost $500 to $1,000 more than aftermarket kits, and you can't change the fob design or add features later. If you're buying a used car, factory remote start is already there and requires no installation.

Installation costs and what affects the price

Professional installation of an aftermarket kit typically costs $300 to $1,500, depending on your vehicle's complexity and the shop's labor rates. Luxury cars, newer models with advanced security systems, and vehicles with push-button ignitions cost more because the installer has to integrate the kit more carefully with the car's computer. A straightforward installation on a 2010 Honda Civic might run $400, while the same kit on a 2022 BMW could cost $1,200.

Some shops charge a flat rate for installation; others charge hourly labor plus the cost of the kit itself. The kit alone ranges from $150 to $600 depending on features. Before you commit, get quotes from at least two shops and ask whether the price includes testing and a warranty on the installation. Many shops offer a one-year warranty on parts and labor, which covers defects but not damage from accidents or water.

Safety features and automatic shutoff

Most auto start kits include a timer that shuts the engine off automatically after 10 to 20 minutes if you don't get in the car and press the brake pedal. This prevents the engine from running unattended for hours, which wastes fuel and can overheat the engine. You can usually adjust the timer length through the fob's programming menu or through a smartphone app if your kit supports it.

The system also won't start the engine if the doors are unlocked or open, and it requires the car to be in Park. Some kits integrate with your car's alarm system, so if someone tries to open a door while the engine is running remotely, the alarm sounds and the engine shuts off. Smartphone-based systems often include geofencing, which notifies you if the car moves beyond a set distance from your phone, adding a layer of theft prevention.

Smartphone apps and two-way communication

Newer auto start kits let you start the engine through a mobile app instead of a key fob. You open the app, tap a button, and the car starts. These systems use cellular data or Bluetooth to communicate with the receiver module in your car. Two-way systems send a signal back to your phone confirming that the engine started, so you know it worked rather than guessing. Some apps also show you the car's location, fuel level, and door lock status.

Smartphone-based remote start usually costs $100 to $300 more than fob-only systems, and it requires a data plan or subscription to the kit manufacturer's cloud service. Plans typically cost $10 to $20 per month. The advantage is convenience—you don't need to carry a separate fob—but the disadvantage is that your phone needs cellular signal or Bluetooth range to work. If your phone battery dies or you forget it, you can't start the car remotely.

Insurance and theft prevention

Some insurance companies offer discounts of 5 to 10 percent on comprehensive coverage (which covers theft) if your car has a remote start system. The logic is that remote start reduces theft risk because you're less likely to leave the car running unattended, and some systems include GPS tracking. However, not all insurers offer this discount, and the amount varies. Contact your insurance agent before installation to ask whether you may have access to and what documentation they need.

The discount usually applies only if the system includes an alarm or immobilizer—a device that prevents the engine from running unless the correct key fob is present. A basic remote start without these features may not reduce your premium. Even if you don't get a discount, the security features of a good kit can give you peace of mind, especially if you live in an area with high car theft rates.

Frequently Asked Questions

Will remote start void my car's warranty?

Factory remote start won't void your warranty because it's installed by the dealership and integrated into the car's system. Aftermarket kits can void your warranty if the installation damages electrical components or if a malfunction is traced back to the kit. Check your vehicle's warranty document or ask the dealership before installation. Many shops carry liability insurance that covers damage they cause during installation.

Can I install a remote start kit myself?

Most people should not attempt DIY installation because it requires wiring into the ignition system and programming the receiver module. Mistakes can damage your car's electrical system or create a fire hazard. If you're experienced with car electronics, some simpler kits come with detailed instructions, but professional installation is safer and usually comes with a warranty.

Does remote start work if my car battery is dead?

No. The receiver module and fob both need power to communicate. If your main battery is completely dead, the remote start won't work. However, the receiver module draws very little power when the car is off, so it won't drain your battery faster than normal.

What happens if I remote start the car and then the battery dies while it's running?

The engine will shut off when the battery is depleted, just as it would if you were driving. The automatic shutoff timer won't prevent this. If this happens repeatedly, you likely have a charging system problem that needs repair regardless of the remote start kit.

Can I use remote start in cold weather?

Yes, and that's one of the main reasons people install these systems. The engine will start in cold weather as long as your battery has enough charge and your fuel isn't gelled. However, the engine may run rough for a few seconds until it warms up, which is normal. Let the car idle for a minute or two before driving in very cold conditions.