Key Takeaways: Why Your Remote Start Is Dead
If you're standing in the driveway freezing because your GMC Terrain refused to start, here is the short list of what usually causes it. Check these first:
- Check Engine Light is On: This is the #1 culprit. If the light is on, remote start is disabled automatically.
- Key Fob Battery: A weak CR2032 battery might unlock doors but fail to send the strong signal needed for starting.
- Hood Latch Sensor: If the car thinks the hood is open (even if its not), it wont start for safety reasons.
- Hazard Lights: Remote start won't work if your hazards are flashing.
- Coolant or Oil Issues: Low pressure or high temps will block the start to save your engine.
The Most Common Culprit: The Check Engine Light
Let's get right into the biggest reason this happens. If your GMC Terrain has a Check Engine Light (CEL) on the dashboard, the remote start feature is automatically disabled. Period.
I know this sounds annoying, but General Motors actually designed it this way for a good reason. When you remote start your car, you aren't sitting in the driver's seat to watch the gauges. If the engine has a serious problem-like a misfire or low oil pressure-running it without a driver present could destroy the engine in minutes.
So, the computer plays it safe. Even a minor code, like a loose gas cap that triggers an emissions warning, will kill the remote start function.
The Fix: You need to clear the code. You can go to an auto parts store like AutoZone or O'Reillys, and they will usually scan the code for free. Once the problem is fixed and the light is off, your remote start should work again immediately.
The Key Fob: It might just be dead
This seems obvious, but we often overlook it because the fob still unlocks the doors. The signal required to unlock a door is much weaker than the continuous signal needed to engage the remote start sequence. Also, we tend to abuse our keys. They get dropped, sat on, and thrown in bags.
Most GMC Terrain key fobs use a CR2032 battery. They are super cheap, you can get them at any grocery store.
How to test if it's the fob:
Do you have a second set of keys? If the second key works perfectly but your main key doesn't, you know the issue is with the fob itself and not the truck. If both keys fail, the problem is likely with the vehicle.
Also, pay attention to how you are pressing the buttons. On most GMC Terrains, the sequence is:
- Press the LOCK button once.
- Immediately press and hold the REMOTE START (semicircle arrow) button for at least 4 seconds.
If you don't press Lock first, it wont work. If you let go of the start button too early, it wont work. The turn signal lamps should flash to tell you it received the command.
The Hood Latch Sensor (The "Invisible" Problem)
This is a classic GM issue. There is a safety switch located in the latch mechanism under the hood of your Terrain. Its job is to tell the computer if the hood is open or closed.
Why does this matter? Imagine a mechanic is working on your engine, his hands are deep inside the belts, and you accidentally sit on your key fob inside the house. If the engine started, it could cause serious injury. So, if the car thinks the hood is up, remote start is totally dead.
The problem is that these sensors get dirty. Road grime, salt, and grease build up in the latch. Sometimes the sensor fails or gets stuck, telling the computer the hood is "OPEN" even when you slammed it shut.
What to do: Pop your hood and look at the latch mechanism. You can try spraying it with some electrical contact cleaner or even just working the latch back and forth to loosen up any grime. If the dashboard explicitly says "Hood Open" when you're driving, this is definitely your problem.
Vehicle Settings in the Infotainment System
Sometimes, technology just glitches, or maybe a battery reset changed your default settings. It is possible that the remote start feature has been toggled "OFF" in your car's computer.
You can check this right from the driver's seat:
- Turn the car on.
- Go to the Settings menu on your touchscreen.
- Select Vehicle.
- Look for Remote Lock, Unlock, Start.
- Make sure Remote Start is selected or toggled to On.
If this was turned off, simply turning it back on fixes the issue instantly.
The Hazard Lights and "Key in Vehicle" Rule
The computer in the GMC Terrain is pretty smart about checking the environment before it fires up the engine. There are two specific scenarios involving keys and lights that will stop the process.
First, Hazard Lights. If your hazard flashers are on, remote start is disabled. I'm not entirely sure why this rule exists-maybe they assume if hazards are on, the car is broken down-but it's in the manual.
Second, Keys inside the car. If you have a push-to-start model and you left a spare key in the cupholder or the glovebox, the car knows. It won't remote start if it detects a fob is already inside the cabin. This is to prevent theft (so someone can't just smash the window and drive off because the car is already running with a key inside).
Doors and Liftgate Sensors
Just like the hood latch, every door and the rear liftgate has a sensor. If the car thinks a door is ajar, it will refuse to start remotely. Usually, you would notice this because your interior dome lights would stay on, or the dash would yell at you that a door is open.
However, sometimes the rear liftgate on the Terrain can be tricky. It might look closed, but it hasn't latched that final "click." Walk around the car and give every door and the trunk a firm push just to be sure.
Engine Safety Parameters
We touched on the Check Engine Light earlier, but there are other engine stats that don't always trigger a light immediately but will still stop a remote start. According to the owner's manual, the vehicle system checks for:
- High Coolant Temperature: If the engine is already too hot, it won't start.
- Low Oil Pressure: If the sensor reads low pressure, it prevents starting to save the bearings.
If you have recently had an oil change, check your oil level. Sometimes if the level is low, the pressure drops, and the computer steps in to protect the car.
The "Maximum Runs" Rule
Did you know there is a limit to how many times you can remote start the car? You are generally allowed two remote starts in between ignition cycles.
A "start" usually lasts for 10 or 15 minutes (depending on your year model). You can extend the time by doing the remote start sequence again, adding another 10 minutes. However, once you have done two remote starts (or one start and one extension), the car says "That's enough."
You have to go out to the car, insert the key (or push the start button), and turn the ignition to ON/RUN to reset the counter.
Advanced Troubleshooting: The BCM
If you have checked the battery, the engine light, the hood latch, and the settings, and it still won't work, we are entering "take it to the shop" territory. The system is controlled by the Body Control Module (BCM).
The BCM is the computer brain that handles windows, locks, lights, and security. Sometimes, the BCM software gets corrupted or the unit itself starts failing. A dealership can re-flash the software, which is basically like reinstalling Windows on a PC. It's not something you can easily do in your driveway without expensive scan tools.
How to attempt a "Hard Reset" (The DIY Last Resort)
Before you pay a mechanic, there is one old-school trick you can try. It's like restarting your router when the internet is slow. You can reset the car's electronics by disconnecting the battery.
Warning: This will reset your radio presets and clock.
- Pop the hood.
- Use a 10mm wrench to loosen the Negative (Black) battery terminal.
- Pull the cable off the post.
- Wait about 15 to 20 minutes. This drains the residual power from the capacitors in the modules.
- Reconnect the cable and tighten it down.
Start the car manually first. Then turn it off, lock it, and try the remote start. Sometimes this clears out temporary glitches in the BCM.
Summary of Steps to Fix It
So, to wrap this up, don't panic. It's rarely a catastrophic failure. Here is your battle plan:
- Look at the dash for a Check Engine Light. If yes, fix that code.
- Replace the battery in your key fob (CR2032).
- Check that the hood is fully closed and the latch isn't gunked up.
- Make sure you aren't leaving a spare key inside the car.
- Check the settings menu on the touchscreen.
- Try the battery disconnect reset.
90% of the time, it's just a Check Engine Light or a bad fob battery. Good luck!
Frequently Asked Questions
Why does my GMC Terrain blink the lights but not start?
If the lights flash (usually the turn signals) but the engine doesn't crank, the car received the signal but rejected the request. This almost always points to a safety inhibitor, like the hood latch sensor, a door being ajar, or a stored Check Engine code. The car hears you, but it's saying "No" for safety.
Can I install remote start if my Terrain didn't come with it?
Yes, you can. You have two options. You can buy an OEM kit from GM which involves a new key fob and a dealer programming the BCM. Or, you can go aftermarket (like Viper or Compustar). Aftermarket systems are usually cheaper and have longer range, but you have to carry an extra fob or deal with extra wiring.
How much does it cost to fix the remote start sensor?
If it is the hood latch sensor (the most common hardware failure), the part is usually between $40 and $80 depending on if you buy generic or OEM. Labor might run you an hour at a shop, so expect a bill around $150–$200 if you don't do it yourself. If it's just a key fob battery, it costs about $5.
Does the OnStar app remote start work if the key fob doesn't?
Usually, no. If the reason the remote start is failing is vehicle-based (like a Check Engine Light or Hood Open), the myGMC app (OnStar) will also fail to start the car. The app sends the same command to the BCM that the key fob does. However, if the issue is just a broken button on your physical key fob, the app will work perfectly.
Will a low car battery prevent remote start?
Yes. If the vehicle battery voltage is too low, the system will disable non-essential functions to ensure there is enough juice to crank the engine manually when you get in. Remote start is considered a luxury, not a necessity, so it gets cut off early when the battery is dying.