FIXED: 2021 silverado remote start not working

The Quick Fix: Why Your Truck Won't Start

If your 2021 Silverado remote start isn't working, check your dashboard for a Check Engine Light (CEL). If that light is on, the truck disables remote start for safety. This is the cause about 80% of the time. If there's no light, the next most common culprits are a dying key fob battery (CR2032), a hood latch that thinks the hood is open, or a loose gas cap.

It is incredibly frustration when you walk out to your truck on a freezing morning, expecting it to be warm, and find it stone cold. I've been there. The 2021 Silverado is a great truck, but the electronics can be a bit sensitive. Let's walk through this together and figure out exactly what's going on with your rig.

1. The Check Engine Light (The Usual Suspect)

I cannot stress this enough-this is almost always the problem. GM programmed these trucks to disable the remote start feature if the onboard computer (ECU) detects any engine trouble codes.

Why do they do this? It's a liability thing. If your engine has low oil pressure or a misfire, Chevy doesn't want the truck running without a driver present to see the warning lights or hear the weird noises. It protects the engine from destroying itself while you're inside drinking coffee.

The "Hidden" Code: Sometimes, you might not even see the light on the dash yet. The code could be "pending." This means the computer saw an error once but is waiting to see it again before lighting up the dashboard. However, even a pending code is enough to kill the remote start.

The Fix:

• Look at your dash. Is the yellow engine light on?
• If yes, you need to scan it. You can go to AutoZone or O'Reillys and they'll scan it for free.
• The Gas Cap Trick: Believe it or not, a loose gas cap throws an emissions code (EVAP leak). If you just got gas recently, go tighten the cap until it clicks, drive it for a day, and see if the light clears.

2. The Hood Latch Sensor

This is a safety feature that people forget about. Under the hood of your Silverado, right near the latch that holds the hood down, there is a tiny electrical switch.

This switch tells the computer if the hood is open or closed. If the truck thinks the hood is open, remote start is disabled. This is so you don't accidentally remote start the truck while a mechanic has their hands inside the fan belt. That would be bad news.

On the 2021 models, this sensor can get gunked up with road salt, mud or grease. Sometimes the connector just gets loose.

How to test it:

1. Get in the truck and turn it on (normal start).
2. Look at the Driver Information Center (the screen between your gauges).
3. Does it say "Hood Open"?
4. If it says the hood is open but you know it's closed, you found your problem. You likely need to clean that sensor or replace the latch assembly.

3. Key Fob Issues (It's not always the truck)

Batteries don't last forever. Even if your fob can still unlock the doors, it might not have enough "juice" to send the continuous long-range signal required for the remote start sequence. Unlocking a door takes a split-second pulse of energy. Remote starting requires a sustained "handshake" with the truck.

The 2021 Silverado uses a CR2032 battery. You can get these at any grocery store or pharmacy.

Replacing the battery is easy:

• Press the chrome button on the side to pull out the physical metal key.
• Take that metal key and stick the tip into the slot where the key just came from, but angle it to pry the two halves of the plastic case apart.
• Don't force it too hard, just twist gently.
• Swap the battery (make sure the positive side with the writing is facing up).
• Snap it back together.

Also, are you doing the sequence right? I know, I know, you've done it a million times. But just humor me. The sequence for the 2021 model is usually: Press LOCK, then immediately press and HOLD the start button (the circle arrow) for 4 seconds. If you just tap the start button, nothing happens.

4. Your Hazard Lights Are On

This is a weird one that gets people. If you left your hazard flashers on-maybe you parked briefly to run into a store or you were unloading something-the remote start won't work.

The system logic prevents remote starting if the hazards are active because the truck assumes it's in a distress situation or being towed. Go out to the truck and make sure that red triangle button isn't pressed.

5. The "Maximum Run" Limit

Did you know there is a limit to how many times you can remote start the truck? According to the owner's manual (and general GM logic), you are only allowed two remote starts between ignition cycles.

Here is how it works:

You remote start it once. It runs for 15 minutes (or 10, depending on settings). It shuts off. You remote start it again to warm it up more. It runs another cycle. It shuts off.

If you try to remote start it a third time, it will not work. You must physically go to the truck, get in, and turn the ignition on with the push-button start to reset the counter.

6. Coolant and Oil Pressure Safety

The truck is smart. Too smart, sometimes. It monitors the vital fluids before allowing the engine to fire up remotely.

• Coolant Temperature: If the engine is already overheating (which shouldn't happen if it's been parked, but maybe a sensor is broken), it wont start.
• Oil Pressure: If the oil pressure sensor is reading critically low, the system blocks the start to save the engine bearings.

Usually, these issues will be accompanied by a Check Engine Light, leading us back to point #1.

7. Settings in the Infotainment System

If you recently had the battery disconnected, or your kid was playing with the screen, the feature might actually be turned off in the software.

Go to your main screen and check this path:

Settings > Vehicle > Remote Lock, Unlock, Start

Look for the "Remote Start" option. Make sure it is toggled to ON. Sometimes a software update over-the-air (OTA) can reset these settings to default, which might be "off" in some regions.

8. Valet Mode

Valet mode is designed to restrict what a parking attendant can do with your truck. It locks out the infotainment system and limits performance. Crucially, it often disables the remote start function to prevent the valet from joyriding or idling your gas away.

Check the top of your infotainment screen or the settings menu to see if Valet Mode is active. You'll need your 4-digit PIN to turn it off if it is.

9. A Second Key is Inside

The 2021 Silverado has proximity sensors for the keys. If you left your spare key inside the center console, in the glove box, or maybe in a gym bag in the back seat, the truck knows.

To prevent vehicle theft (and to stop you from locking your keys inside), the remote start is often disabled if the truck detects a fob is already inside the cabin. Find that spare key and get it out of the truck.

10. The "Global Reset" (The IT Crowd Fix)

If you have checked the battery, the engine light, the hood latch, and the settings, and it still isn't working, the computer might just be glitched. These trucks are basically big computers on wheels now, and sometimes they need a reboot.

Here is how to do a hard reset on the electrical system:

1. Pop the hood.
2. Locate the Negative (-) battery terminal. It's the black one.
3. Use a 10mm wrench to loosen the nut.
4. Pull the black cable off the battery post.
5. Wait about 5 to 10 minutes. Go grab a drink.
6. Put the cable back on and tighten it up.

This forces all the modules in the truck (BCM, ECM, etc.) to restart. You might lose your radio presets, but it often fixes weird electrical gremlins like a non-functioning remote start.

11. Aftermarket Remote Starters

Did you buy the truck used? It's possible the previous owner installed an aftermarket remote start rather than the factory GM one. This is common on lower trim levels like the Work Truck (WT) or Custom.

If you have an extra little fob on your keychain, or if you are pressing "Lock-Unlock-Lock" to start it, that is an aftermarket system. These are notoriously finicky. They usually have a toggle switch under the dashboard to turn them on and off (valet switch). If you kicked that switch with your boot, you might have turned the system off. Look under the steering wheel for a small black switch or a little LED light.

When to see the Dealer

If you've done all of the above-no check engine light, new fob battery, hood is closed, reset the truck-and it's still dead, you might have a bad BCM (Body Control Module) or a failed remote start receiver.

Since this is a 2021 model, check your warranty status. If you are under 36,000 miles, this should absolutely be covered under the bumper-to-bumper warranty. Don't stress yourself out trying to fix a fried computer module; let Chevy pay for it.

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Frequently Asked Questions

Why does my Silverado start but then turn off after a few seconds?

This is usually a "stall" caused by a system check failure immediately after startup. The most common reason is that the engine RPMs dropped too low (dirty throttle body) or the oil pressure didn't build up fast enough. It can also happen if the fuel level is extremely low. The system shuts down to protect the truck.

Can I extend the run time longer than 15 minutes?

Yes, you can extend it once. While the truck is running on the first remote start cycle, repeat the remote start sequence on your fob. This will add another 15 minutes to the current time. You can't do this indefinitely, though. After about 30 minutes total, you have to drive the truck.

My app works to start the truck, but the key fob doesn't. Why?

This is a great diagnostic clue. If the MyChevrolet app starts the truck successfully, but the key fob doesn't, your truck is fine! The problem is 100% with your key fob. It's either the battery in the fob, the buttons are worn out, or the fob has lost its programming and needs to be re-paired to the truck by a locksmith or dealer.

Does the remote start turn on the heated seats?

It should, but it depends on the outside temperature. In the 2021 Silverado, there is a setting in the infotainment menu called "Remote Start Auto Heat Seats." If this is checked, and the outside temp is below roughly 50 degrees, the heated seats will kick on. However, the lights on the seat buttons won't always light up until you get in and push the start button. Touch the leather-if it's warm, it's working.

Will a "Stored" code stop remote start?

Yes. Even if the Check Engine Light isn't currently blazing on your dash, a "Permanent" or "Stored" code in the history can prevent remote start until the drive cycle completes and the computer is satisfied the problem is gone. You might need to clear the codes with a scanner to get it working again immediately.