What remote start does and how it works
Remote start is a system that lets you turn on your car's engine from outside the vehicle, usually from 100 to 1,000 feet away using a key fob or smartphone app. When you press the button, a receiver in your car signals the starter motor to crank the engine, and the heating or air conditioning begins running before you get inside.
The system works through a wireless transmitter in your key fob or phone that communicates with a receiver module installed in your vehicle. That receiver is wired to your car's ignition and starter systems. Some remote start systems are factory-installed by the manufacturer; others are aftermarket units that a technician adds later. The range and features vary depending on the system — some can start your car from across town if your phone has a data connection, while others work only within a few hundred feet.
Remote start does not unlock your doors or put the car in gear. Your car will start and idle, but the transmission stays in Park (or Neutral on manual transmissions), and you still need your key to unlock and drive away. This safety feature prevents the car from rolling or being driven away remotely.
Key Takeaways
- Remote start turns on your engine from outside the car using a key fob or phone app, so the cabin heats or cools before you arrive.
- Factory systems come built into newer vehicles, while aftermarket systems can be installed on older cars by a technician for $300 to $1,500 depending on complexity.
- Your car will not unlock or shift into gear when started remotely, so you still need your key to drive away.
- Remote start drains your battery slightly each time you use it and may void your warranty if installed incorrectly on a newer vehicle.
- Some insurance companies offer small discounts for remote start because the feature reduces theft risk and engine strain from cold starts.
Factory remote start versus aftermarket systems
Most new cars sold today come with remote start built in by the manufacturer. If your vehicle has it, the button is usually on your key fob or accessible through your car's smartphone app. Factory systems are integrated into your car's electrical and security systems, so they work reliably and do not affect your warranty. You straightforward use the feature that came with your car.
If your car did not come with remote start and you want to add it, you can have an aftermarket system installed. A technician will run wiring from your car's battery and ignition to a receiver module, usually hidden under the dashboard or behind a panel. The cost ranges from $300 to $1,500 depending on your car's make and model — some vehicles are much harder to wire than others. Aftermarket installation on a newer car may void your manufacturer's warranty on electrical components, so check your warranty terms before proceeding.
Aftermarket systems vary in quality and range. Basic systems work within a few hundred feet using a standard key fob. Premium systems use your phone's data connection and can start your car from anywhere, though they require a subscription (usually $10 to $20 per month) to the system provider's cloud service.
What happens when you use remote start
When you press the remote start button, your car's engine cranks and begins running. The idle speed is usually higher than normal — around 1,200 to 1,500 RPM — to warm the engine quickly. Your heating or air conditioning runs on the settings you last used, so if you had the heat on when you parked, it will be on when the engine starts remotely.
Most remote start systems run for 10 to 20 minutes before shutting off automatically. This prevents the engine from running indefinitely if you forget about it, and it saves fuel and battery. Some systems let you extend the runtime by pressing the button again, or you can set a custom timer through your car's app.
The engine will shut off when ready if you unlock the car with your key or key fob — the system assumes you are getting in and taking over. If you do not unlock the car, the engine idles until the timer runs out, then stops on its own.
Battery drain and fuel use
Each remote start uses a small amount of battery power to send the wireless signal and crank the engine. If you use remote start once or twice a day, the battery drain is negligible — your car's alternator replaces the power while you drive. If you use it many times daily or your battery is already weak, you may notice the battery drains faster than usual.
Remote start also uses fuel. A 10-minute idle session burns roughly 0.1 to 0.2 gallons of fuel depending on your engine size. Over a winter, if you use remote start daily, that adds up to several gallons. However, many people find the trade-off worth it because warming the engine before driving reduces engine wear and improves fuel economy during the actual drive — a cold engine burns more fuel and wears faster than a warm one.
Safety and security considerations
Remote start is designed with safety limits. Your car will not shift out of Park when started remotely, and the doors remain locked unless you unlock them separately. This prevents the car from rolling or being driven away. However, if your car is parked on a steep hill or in an unsafe location, the engine running unattended for several minutes is still a risk — someone could break a window or tamper with the car while it idles.
From a security standpoint, remote start actually reduces theft risk in some cases. A car that starts remotely is less likely to be stolen because a thief cannot straightforward hotwire it — the system requires the correct wireless signal. However, aftermarket systems installed poorly or using outdated encryption can be vulnerable to signal jamming or hacking, so installation quality matters.
Never use remote start to warm up your car in an enclosed space like a garage. Engine exhaust contains carbon monoxide, which is deadly in enclosed areas. Always remote start your car outdoors or in a well-ventilated space.
Insurance and warranty implications
Some insurance companies offer small discounts — typically $5 to $15 per year — for vehicles with remote start, because the feature reduces theft risk and engine strain. Check with your insurance agent to see if your policy qualifies for a discount.
Factory remote start does not affect your warranty. Aftermarket remote start may void your manufacturer's warranty on electrical and engine components if the installation is done incorrectly or if the system interferes with your car's computer. Before having an aftermarket system installed, ask the technician whether the work will affect your warranty, and get that answer in writing. A reputable shop will stand behind their work and offer a warranty on the installation itself.
Troubleshooting common remote start problems
If your remote start stops working, the most common cause is a dead or dying battery in your key fob. Replace the fob battery first — it costs $5 to $15 and takes a few minutes. If that does not fix it, check whether your car's battery is low. A weak car battery may not have enough power to crank the engine remotely, even though it starts normally with the key.
If your car has a factory remote start app and it stops working, check your phone's internet connection and make sure the app is up to date. Log out and log back in to your account. If the problem persists, contact your car manufacturer's customer service — they can reset your account or troubleshoot the app connection.
Aftermarket systems sometimes lose their programming if your car's battery dies or is disconnected. If this happens, the system will not respond to your key fob. A technician can reprogram the receiver module, usually in 30 minutes to an hour, for $50 to $150.
Frequently Asked Questions
Does remote start work if my car is locked?
Yes. Remote start works whether your car is locked or unlocked. The engine will crank and run, but the doors stay locked unless you unlock them separately with your key fob or key. This is a safety feature — it prevents someone from driving away in your car remotely.
Can I remote start a car with a manual transmission?
Yes, but the system works differently. A manual transmission car will start in Neutral rather than Park, and the clutch pedal must be fully depressed (or the system will not start the engine). Most aftermarket systems for manual cars require a technician to wire the clutch switch into the remote start receiver so the system knows the clutch is in.
Will remote start drain my battery if I do not use it?
No. The receiver module draws a tiny amount of power even when the car is off, but it is negligible — similar to a car alarm or security system. You will not notice battery drain from the remote start system itself unless you are using the feature multiple times daily or your battery is already weak.
What is the range of remote start?
Factory systems and basic aftermarket key fob systems typically work within 100 to 1,000 feet, depending on obstacles and interference. Premium smartphone-based systems can work from anywhere with a data connection, but they require a paid subscription to the system provider's service.
Can I remote start my car in cold weather?
Yes, remote start works in cold weather and is actually one of the main reasons people use it. In freezing temperatures, warming the engine and cabin before you drive improves comfort and reduces engine strain. However, extremely cold weather (below −20°F) can make it harder for the starter motor to turn the engine over, so the system may take longer to start or may not start at all if your battery is weak.