FIXED: gmc remote start not working

The Check Engine Light Rule (The #1 Reason)

I’m gonna be real with you, this is the most annoying feature but it's there for a reason. If your "Check Engine" light (CEL) is illuminated on the dashboard, your GMC simply will not remote start. It doesn't matter if the issue is minor or major.

The computer in your truck, often called the ECU, disables remote start to protect the engine. Since you aren't in the car to see oil pressure dropping or temperatures rising, the car decides it's safer to just stay off.

What to do:

You need to figure out why that light is on. Sometimes its really simple. Did you just get gas? A loose gas cap can trigger an emissions code, which turns on the light, which kills the remote start. Tighten the cap and drive for a few days; the light might go off on its own.

If it's not the gas cap, you need to read the codes. You can go to an auto parts store like AutoZone or O'Reilly, and they will usually scan it for free. Or, grab a cheap OBDII scanner off Amazon for twenty bucks. Once you fix the problem and clear the code, your remote start should work instantly.

The Hood Latch Sensor Issue

If your Check Engine Light is not on, look at the hood. Does your dashboard say "Hood Open" even when it's closed? If so, you found your problem.

GMC vehicles have a safety switch in the hood latch. This ensures that the engine doesn't remote start while a mechanic has their hands near the fan belts. It's a great safety feature, but the sensors GMC uses are known to get dirty or fail.

If that sensor breaks, the circuit stays "open," telling the computer the hood is up. The car refuses to start because it thinks it's saving someone's fingers.

The Fix:

First, try opening and slamming the hood shut. Sometimes it just didn't latch all the way. If that doesn't work, locate the sensor near the latch mechanism. You can try cleaning it with some electrical contact cleaner. If it's totally busted, a replacement latch assembly is usually pretty cheap, around $50 to $100 depending on the model, and it's an easy DIY swap.

The "Two Start" Limit

This one catches a lot of people off guard. GMC limits how many times you can remote start the vehicle without physically driving it.

Here is how the math works:

• You remote start the car (runs for 10-15 mins).
• It shuts off, or you extend the time (another 10-15 mins).
• Once you have performed two remote starts, the feature is disabled.

The system does this to prevent carbon monoxide buildup if you accidentally started the car in a garage, and to save fuel. If you've been trying to start it over and over to warm it up on a freezing day, you might have hit the limit.

The Fix: This is the easiest one. Go out to the truck, unlock it, put the key in (or push the start button), and turn the ignition to the "Run" position. This resets the counter. Turn it off, lock the doors, and try the remote start again. It should work.

Key Fob Troubles

We often blame the truck, but sometimes the remote itself is just tired. Even if the remote can unlock the doors, the battery might be too weak to send the remote start signal. The start signal requires a long press (or a specific sequence), which draws more sustained power than a quick "unlock" blip.

Also, make sure you are doing the sequence right. On most GMCs, you have to press the Lock button first, and then immediately press and hold the Start button (the circle arrow) for at least 4 seconds. If you just press the start button without locking first, nothing happens. This is to prevent accidental starts in your pocket.

Checking the Battery:

Most GMC fobs use a CR2032 battery. They are cheap. If you haven't changed yours in 2 or 3 years, just do it. It's like five bucks and takes two minutes. Pop the fob open with a small flathead screwdriver or a coin, swap the battery, and snap it back together. You usually don't need to reprogram anything after a battery swap.

Other Safety Lockouts

Your GMC is pretty smart. It runs a quick system check before it allows the engine to fire up. If any of these conditions are met, it will deny the request:

1. Hazard Lights Are On

If you left your emergency flashers on, remote start is disabled. I know, it seems random, but according to the owner's manual in most Sierras and Yukons, this is a standard lockout. Turn off the flashers and try again.

2. Key is Inside the Vehicle

If you have a spare key hidden in the glove box or center console, the car knows. It won't remote start if it detects a fob inside the cabin. This is to prevent theft. Make sure your second set of keys is actually in the house, not in the cup holder.

3. Doors or Trunk Open

This is similar to the hood issue. If a door isn't closed all the way, or the rear hatch/liftgate is slightly ajar, the system locks out. Walk around the car and make sure everything is shut tight. Look for the "Door Ajar" warning on the dash.

4. Low Vehicle Battery

I'm talking about the big 12-volt battery under the hood, not the key fob. If your truck's battery voltage is low, the computer goes into "power save" mode. It prioritizes keeping enough juice to start the car when you physically get in, rather than wasting energy on a remote start. If your crank sounds slow when you start it manually, your battery might be on its way out.

5. Coolant and Oil Pressure

This is rare, but if the car detects extremely low oil pressure or coolant temperatures that are way too high (from the last drive), it won't start remotely. It's protecting the mechanical components.

The Transmission Check

This sounds obvious, but you'd be surprised. The gear selector must be in Park. If the shifter cable is a little loose and the truck thinks it's in Reverse or Neutral, it won't start.

Sometimes, the little indicator on the dash might say "P", but the switch on the transmission isn't quite there. Try shifting to Neutral and then firmly back into Park. Make sure it clicks. If you have an older GMC, wiggling the shifter while in Park might make the contact connect.

Aftermarket Remote Starters

Did you buy the truck used? It might have an aftermarket starter (like Viper or Compustar) installed. These don't always behave the same way as the factory GMC system.

If you have an extra remote on your keychain that doesn't look like the factory one, or if you press the lock button 3 times to start it (a common aftermarket setup), you are dealing with a different beast. These systems often have a "Valet Mode." If you accidentally toggled a switch under the dash or pressed a button combo on the remote, Valet Mode disables the remote start so mechanics don't get surprised.

Look for a small toggle switch near the driver's kick panel or check the manual for your specific aftermarket brand to turn off Valet Mode.

Using the myGMC App

If your physical fob works but the myGMC app isn't starting the car, that's usually a network or account issue. This happens a lot more than mechanical failure.

• Subscription Status: GMC moved the remote start feature behind a paywall for many models. If your OnStar or Connected Services trial expired, the app button simply won't work anymore. You have to pay the monthly fee to get it back.
• Cell Signal: The car needs a cellular signal (AT&T usually) to receive the command from the app. If your truck is parked deep in a concrete parking garage, it might not have service.
• App Glitches: Sometimes the app just sucks. Sign out, delete the app, reinstall it, and sign back in. It clears the cache and fixes weird connection bugs.

When to Call a Pro

If you have checked the engine light, replaced the fob battery, ensured the hood is closed, and reset the ignition, and it still won't work, you might have a deeper electrical issue.

At this point, it could be a Body Control Module (BCM) problem. The BCM is the computer that controls accessories like locks, lights, and remote start. If it's acting up, it might need a software update or replacement. That is something only a dealership or a high-end shop with GM programming tools can handle.

Also, check your warranty. If you are under 36,000 miles (or have an extended warranty), this diagnosis should be free at the dealer.

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Frequently Asked Questions

Does the check engine light disable remote start on all GMCs?

Yes. Pretty much every GM vehicle (GMC, Chevy, Cadillac, Buick) made in the last 15+ years is programmed this way. It prevents the engine from running unsupervised when there is a known fault.

Can I bypass the check engine light remote start disable?

Not easily. There isn't a "switch" to flip. The only way to bypass it is to fix the problem causing the light, or clear the code with a scanner (though the light will come back if the part is still broken). Some aftermarket remote starters ignore the check engine light, but the factory one won't.

How do I know if my remote start is in Valet Mode?

Factory GMC systems don't typically have a "Valet Mode" that users toggle. However, if you have an aftermarket system, usually the parking lights won't flash when you lock/unlock, or the LED on the antenna (on the windshield) will stay solid instead of blinking. Consult the manual for your specific alarm brand.

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

If the parking lights flash when you try to remote start, the car received the signal. If it refuses to crank, it is almost certainly a safety lockout (Check Engine Light, Hood Open, or Low Battery). The car is acknowledging you, but saying "No."

Is there a fuse for remote start?

Remote start isn't usually on a single fuse. It's a function integrated into the Body Control Module. However, checking fuses for the "Ignition," "BCM," or "Door Locks" is a good idea if other things in the car aren't working either.

Hopefully, this helps you get your truck started! There is nothing worse than walking out to a cold car in the winter. Good luck fixing it.