Why Doesn'T My Remote Start Work On My Car

The most likely reason your remote start isn't working is simply a dead battery in your key fob, a "Check Engine" light on your dashboard, or a faulty hood latch sensor. If you push the button and nothing happens-or the lights flash but the engine doesn't crank-the car’s computer is likely preventing the start to protect the vehicle or for safety reasons.

It's frustrating, I know. You bought the car so you wouldn't have to sit in a freezing seat, and now you're stuck troubleshooting in the cold. But don't worry, most of the time this is an easy fix you can do yourself without paying a mechanic.

Here is a breakdown of exactly why this happens and how to fix it.

1. The Key Fob Battery is Dead (Or Dying)

Lets start with the easiest thing. Even if your fob still unlocks the doors, it might not have enough juice to send the remote start signal. The remote start signal usually requires a longer, stronger transmission than just popping the door lock.

If you have a 2-way remote (the kind with a little LCD screen or lights that confirm the car started), these eat through batteries way faster than standard fobs. If the little light on your remote doesn't flash when you press the button, or if the range has gotten terrible lately, its the battery.

How to fix it

Pop the remote open. usually there's a small slot on the side you can twist with a coin or a flathead screwdriver. Most of them take a CR2032 battery which you can buy at any grocery store. Swap it out and try again. If you have a spare key, try that one. If the spare works, you know the problem is just your main remote.

2. Your Check Engine Light Is On

This is the one that catches people off guard. You might have a "Check Engine" light (CEL) on for something totally minor, like a loose gas cap or a small EVAP leak. You figure you'll get to it later because the car drives fine.

However, almost every car manufacturer-from Ford to Toyota-programs their vehicles to disable remote start if the CEL is on. The logic is actually pretty smart. The car doesn't know if the problem is minor or if the engine is about to explode. Since remote start happens without a driver in the seat to watch the gauges, the computer disables the feature to prevent engine damage.

According to most owner's manuals, the system is designed to "prevent remote starting if a powertrain malfunction is present."

What to do

Look at your dashboard when you start the car manually. Is the yellow engine light on? If yes, that is your problem. You need to clear the code or fix the issue. Sometimes, just tightening your gas cap and driving for a few miles will clear it and bring your remote start back to life.

3. The Hood Pin Switch is Broken

This is probably the most common mechanical failure for remote starters. Under your hood, there is a safety switch (often called a hood pin or tilt switch). Its job is to tell the car if the hood is open.

Why does this matter? Safety. Imagine a mechanic is working on your engine, their hands are deep inside the belts, and you accidentally sit on your key fob inside the house. If the engine started, it could seriously injure them. So, if the car thinks the hood is up, it refuses to start.

Over time, these switches get corroded, bent, or dirty. Even if your hood is physically closed, the switch might be reading "OPEN."

How to check it

Most cars will show a "Hood Open" warning on the dashboard if this switch is failing. If you don't have a screen that tells you that, try this: pressing the remote start button and watch the parking lights. If they flash a specific number of times (usually rapid flashing), that is often an error code telling you a safety zone is active.

You can try finding the switch near the hood latch and wiggling it or cleaning it with some alcohol. If its an aftermarket system (like Viper or Compustar), the pin is usually a noticeable plunger switch along the edge of the engine bay.

4. You Are in "Valet Mode"

If you have an aftermarket remote start, you might have accidentally put it in Valet Mode. This is a mode designed for when you hand your keys to a parking attendant. It allows them to lock and unlock the car, but it disables the alarm and the remote start so they can't accidentally set it off.

People usually trigger this by accident. Maybe you pressed a button combination on the remote while it was in your pocket, or you hit the switch under the dashboard with your foot.

Getting out of Valet Mode

For many systems, the parking lights will not flash when you lock the doors if you are in Valet Mode. The process to exit this mode varies, but for many Viper systems, you open the door, turn the ignition to "On" (don't start it), and tap the Valet button (usually hidden under the dash) once. But you really should check the manual for your specific brand because they are all different.

5. You've Hit the Maximum Start Limit

Did you know there is a limit to how many times you can remote start your car without driving it? Most factory systems allow you to remote start the car two times.

For example, you start it, it runs for 10 or 15 minutes, and shuts off. You start it again, it runs another cycle, and shuts off. If you try to do it a third time, the car will ignore you. It does this to prevent carbon monoxide buildup if you accidentally started it in a garage, and to stop you from draining the gas tank.

To reset this counter, you just have to go out to the car, insert the key (or push the start button), and turn the ignition fully on. Once you cycle the ignition with the actual key, the remote start counter resets.

6. Your Coolant or Oil Pressure is Issues

This ties back to the Check Engine Light, but sometimes it happens without a light. Some sophisticated factory systems monitor oil pressure and coolant temperature specifically during the remote start sequence.

If the car is extremely low on oil, or if the coolant temperature sensor is giving a weird reading (like saying the engine is already overheating when it's -10 degrees outside), the computer will abort the start. It basically tries to crank, sees a scary number from a sensor, and kills the engine immediately to save itself.

7. The Hazard Lights are On

This is a weird one, but I've seen it happen. On some newer vehicles, specifically some Honda and Acura models, the remote start will not function if the hazard lights are flashing. If you parked quickly and left them on, or if a door isn't closed all the way and the hazards are flashing as a warning, the remote start command is ignored.

8. Low Fuel Level

Newer cars are getting smarter. If your "Low Fuel" light is on, many factory remote starters will refuse to engage. The logic is that the car doesn't want to run at idle and burn up the last gallon of gas, leaving you stranded in your driveway with a dead car.

If you are running on fumes, go fill up. That might be the only reason it's not working.

9. Factory vs. Aftermarket: Knowing the Difference

Troubleshooting is slightly different depending on if your car came with the remote start or if you had it installed at a shop (like Best Buy or a local audio place).

Factory Systems (Ford, Chevy, Honda, etc.):
These are integrated deeply into the car’s computer. If these fail, it's usually a safety sensor (hood latch, door latch) or a Check Engine Light. You usually can't "reset" these yourself easily without a diagnostic tool.

Aftermarket Systems (Viper, Compustar, Python):
These systems have their own "brain" usually zip-tied under your dashboard. Sometimes these brains just freeze up, kind of like your laptop does.

If you have an aftermarket system that's acting weird, you can try a hard reset. Unplug the main harness going into the remote start box for a minute and plug it back in. Just be careful not to mess with the wiring.

10. It’s Just Too Cold (Irony at its finest)

It sounds ridiculous because the whole point of remote start is for cold weather, but extreme cold can cause failure. If your car battery is old, the voltage might drop too low when the temperature hits zero.

The remote start system needs a certain amount of voltage to function. If your battery is weak, it might have enough power to crank the engine manually, but the voltage drop during the crank might cause the remote start brain to "brown out" and reset. If your car struggles to start when you turn the key, your battery is probably too weak to support remote starting.

Troubleshooting Checklist

Before you take it to a shop, run through this quick list:

• Step 1: Change the battery in the remote.
• Step 2: ensure the hood, trunk, and all doors are slammed shut.
• Step 3: Start the car with the key and check for warning lights.
• Step 4: Check if your car is in "Valet Mode" (look for an LED that stays solid blue or red).
• Step 5: Make sure you aren't out of gas.

If you've done all that and it still doesn't work, you might have a blown fuse or a disconnected wire. At that point, it’s worth taking it to a professional, especially if it's an aftermarket system where a wire might have wiggled loose under the dash.

Frequently Asked Questions

Can I reset my remote starter myself?

If it is an aftermarket system, yes. Usually, you can unplug the antenna or the main power harness on the control module for 30 seconds to reset it. If it is a factory system that came with the car, you generally cannot reset the module yourself without disconnecting the main car battery, which might mess up your radio presets and other settings.

Why do my lights flash but the car won't start?

The flashing lights are actually a code! Count the flashes. For example, on many systems, 3 flashes means the hood is open, and 7 flashes means the car is in gear (or the neutral safety switch is bad). Check your owner’s manual for the "Remote Start Error Codes."

Does a check engine light disable remote start?

Yes, on almost all modern vehicles (2010 and newer). The computer disables remote functions to prevent potential damage to the engine since you aren't inside to monitor the gauges.

How much does it cost to fix a remote start?

If it's just a battery, it's $5. If it's a hood pin switch, the part is usually around $15–$20 and you can often install it yourself. If the control module is fried, you might be looking at $200+ for a replacement.

Can extreme cold stop remote start from working?

Yes. If your car battery is weak (low Cold Cranking Amps), the voltage drop when the starter engages can cause the remote start system to lose power and abort the start. If your battery is more than 3 or 4 years old, get it tested.