Key Takeaways
- The 3G Sunset is the main culprit: Toyota discontinued 3G services late in 2022, which killed the app-based remote start for many 2020 models.
- Check your subscription: Even the key fob method (Press Lock 3 times) often requires an active Remote Connect subscription, which might not be renewable anymore.
- Hood Latch Sensor: If the truck thinks the hood is open, it will absolutely refuse to start.
- The Fix: For most people, the best solution is installing a plug-and-play aftermarket kit (like Start-X) to bypass the Toyota subscription mess.
- Troubleshooting: Check Engine lights and low battery voltage will also disable the system for safety.
The Short Answer: Why It's Not Working
If your 2020 Tundra remote start suddenly stopped working, it is most likely because the 3G cellular network it relied on was shut down, or your "Remote Connect" subscription expired. Toyota used older 3G technology in the 2018–2020 Tundras. When major carriers like AT&T and Verizon turned off their 3G towers in 2022 to make room for 5G, the communication module in your truck basically went blind.
Here is the kicker that annoys everyone: Even though using the key fob (Lock-Lock-Hold) uses a short-range radio signal and not the cellular network, Toyota’s software often checks for an active subscription to allow it to work. If the truck can't "phone home" to verify you pay them money, it disables the feature. It feels like a scam but that is how they programmed the ECU.
If you want it fixed permanently you usually have two choices: go to the dealer for a very expensive retrofit (if they even offer it) or spend about $150–$200 on an aftermarket plug-and-play kit. Most of us choose the latter.
The "3G Sunset" Explained (In Plain English)
Let's dig a little deeper because this is confusing for a lot of owners. Your 2020 Tundra is a beast of a truck, but its brain regarding connectivity was a bit outdated when it rolled off the line. It used a DCM (Data Communication Module) that runs on 3G.
According to telecommunications history, 3G was the standard for a long time. But technology moves fast. When the networks decided to kill 3G, Toyota issued a "Service Campaign" for some vehicles, but for many Tundras, the functionality just ceased to exist.
If you were using the Toyota App on your phone to start the truck from your kitchen, that is definitely gone forever unless you had a retrofit done. The truck literally cannot receive the signal from the internet anymore. It’s like trying to send a fax to a disconnected number.
What About the Key Fob?
This is where it gets controversial. You might be thinking, "But my key fob doesn't use the internet, it uses radio waves." You are right. However, on the Audio Plus and Premium Audio packages, the functionality of the key fob remote start is tied to the software license.
If the subscription lapses-or if the truck can't connect to the network to verify the subscription-the computer in the truck ignores the "start" command from the fob. It’s a software lock, not a hardware failure.
Troubleshooting: Is It Something Else?
Before you go out and buy an aftermarket kit, we should rule out the simple stuff. Sometimes the truck is fine, but a safety sensor is tripping it up. The Tundra has several safety parameters that will prevent a remote start to keep you from accidentally hurting the engine or a person.
1. The Hood Latch Sensor
This is probably the number one hardware cause for remote start failure on Tundras. There is a small switch in the latch mechanism under the hood. Its job is to tell the computer if the hood is popped. If the truck thinks the hood is open, it disables remote start so that the engine doesn't fire up while a mechanic has their hands near the fan belt.
The sensor gets dirty, corroded or just bent over time. If you press the lock button on your fob and you don't hear the confirm beep, or if your alarm goes off randomly at night, it's usually this hood latch switch. You can try cleaning it with some contact cleaner, but you might need to replace the latch assembly.
2. The Check Engine Light (CEL)
Look at your dashboard. Is the Check Engine Light on? If the truck has thrown a code for anything-even a loose gas cap or a minor emissions leak-the system disables remote start. This is a safety feature designed to prevent damaging the engine further by running it unattended.
If you have a CEL, you gotta get that code read and cleared first. Once the light is off the remote start should come back (assuming the subscription issue isn't the problem).
3. Battery Voltage
Tundras need a strong crank to get that V8 turning. If your 12V battery is getting old or the voltage drops below a certain threshold, the Remote Start system will abort. It does this to save enough juice so you can eventually unlock the doors and start it with the key.
If your battery is more than 3 or 4 years old, have it tested at an auto parts store. A weak battery causes all sorts of weird electrical gremlins in modern Toyotas.
4. Door Locks and Windows
The system is picky. For the remote start to engage:
- All doors must be closed.
- All doors must be locked.
- Windows usually don't matter for the start, but if a door is ajar, it's a no-go.
Also, make sure the transmission is fully in Park. It sounds silly but sometimes the shifter doesn't seat all the way.
The "Lock-Lock-Hold" Method (Are You Doing It Right?)
If you still have an active subscription or a working fob system, you have to get the timing right. I've seen plenty of people say "it's broken" when they were just clicking too fast or too slow.
The sequence is:
- Press LOCK (wait for the beep/flash).
- Press LOCK again (wait for the beep/flash).
- Press and HOLD LOCK for 3 seconds.
Don't just mash the button three times fast. It's a rhythm. Click... Click... Hoooooold. Watch the hazard lights. They should flash in response to the first two clicks. On the third hold, the lights should flash repeatedly, and then the engine should crank.
The Permanent Fix: Aftermarket Kits
Okay so let's say you are a victim of the 3G shutdown, or you just don't want to pay Toyota a monthly fee to start your own truck. This is what I did and what most guys on the forums recommend.
You need a "Plug-and-Play" remote starter. The most popular ones are from brands like Start-X, 12volt.solutions, or Accessorides.
Why Go Aftermarket?
- No Subscription: You pay once for the hardware and never pay again.
- Uses Factory Fob: You don't need to carry an extra remote. You just use the standard Lock-Lock-Lock sequence on your existing Toyota key.
- Reliable: These bypass the complicated Toyota telematics module. It talks directly to the truck's computer.
Installation is Easier Than You Think
I am not a mechanic. I can barely change my own oil without making a mess. But I installed a Start-X kit in my driveway in about 20 minutes.
On the 2020 Tundra, it is almost entirely plug-and-play. You basically:
- Take off the plastic cover under the steering column (usually just a few screws or clips).
- Unplug a connector from the truck.
- Plug the T-harness from the kit in between the truck and the plug you just removed.
- Zip-tie the little black box up under the dash so it doesn't rattle.
- Put the plastic cover back on.
That's it. You might have to do a quick "programming" sequence which involves turning the key to the "On" position a few times to let the box learn your key code, but the instructions are super clear. There is no wire cutting or splicing involved.
Long Range Options
The only downside to using the factory key fob is the range. If you can't see your truck, the remote probably won't reach it. The Toyota fob has pretty terrible range, maybe 50-100 feet if you're lucky.
If you need to start your truck from inside a massive office building or a shopping mall, you can get an add-on kit for these aftermarket starters. They make "Long Range" remotes (little separate fobs) that can reach up to a mile. Or, you can add a cellular module (like DroneMobile) which brings back the app functionality on your phone. Yes, you have to pay a subscription for DroneMobile, but it uses 4G/LTE networks, so it actually works, unlike the old Toyota system.
A Note on "Valet Mode"
Most Tundras don't have a specific valet switch for the alarm that is easy to hit, but some aftermarket alarms do. If you bought your truck used, inspect under the dash. If you see a weird little toggle switch or a flashing blue LED that doesn't look stock, the previous owner might have installed a third-party alarm that is interfering with the remote start.
If the system is in Valet Mode, remote start is disabled to prevent a parking attendant from joyriding or messing with settings. usually, you have to turn the key on and off a certain number of times to reset this.
Cost Breakdown
Just to give you an idea of what you are looking at to fix this:
- Checking the hood latch: Free (or $5 for contact cleaner).
- Replacing hood latch: ~$150 for the part if you DIY.
- Start-X Remote Start Kit: ~$150 to $200 on Amazon.
- Dealer Diagnosis: $150/hour (and they might just tell you "sorry, 3G is down").
- Cellular Add-on (DroneMobile): ~$150 for hardware + ~$5/month plan.
Honestly, the $150 aftermarket kit is the best money you will spend. It just works. You don't have to worry about Toyota changing their terms of service or networks going down.
Summary
So, to wrap this up. If your 2020 Tundra won't start remotely, check your engine light and hood latch first. If those are good, you are likely a victim of the 3G network sunset. Toyota's solution is practically non-existent or expensive.
Don't bang your head against the wall trying to get the app to work. Grab a plug-and-play kit, spend 20 minutes under the dash with a screwdriver, and get your warm truck back for the winter. It’s annoying that a 2020 truck has "obsolete" tech, but at least the fix is relatively cheap and easy.
Frequently Asked Questions
Q: Will installing an aftermarket remote start void my warranty?
A: Generally, no. In the US, the Magnuson-Moss Warranty Act protects you. A dealer cannot deny a warranty claim just because you installed an aftermarket part unless they can prove that part caused the specific failure. Since these kits are plug-and-play and don't cut wires, they are very safe. Just unplug it if you are worried before taking it in for service.
Q: Can I still use the Toyota App to start my 2020 Tundra?
A: For most 2020 models, the answer is no. The app relied on 3G networks which are gone. Unless Toyota contacted you for a specific hardware retrofit (which is rare), the app functionality is dead. You need an aftermarket system like DroneMobile to get app features back.
Q: Why does my truck shut off when I open the door?
A: This is a standard Toyota safety feature, often called "Takeover." Most Toyota push-to-start vehicles (and even key-start ones) kill the engine when you open the door after a remote start. It prevents theft. It is annoying, but it's normal behavior for the Tundra. You just have to hop in and restart it.
Q: Does the Start-X kit work on the Tundra with a regular key (non-push start)?
A: Yes! In fact, most 2020 Tundras are key-start (G-Key or H-Key). Make sure you buy the specific kit for "Key Start" Tundras. They differ slightly from the Push-to-Start kits.
Q: My remote start works but the truck runs for only 10 minutes?
A: That is the factory default runtime. It’s to save gas and prevent carbon monoxide buildup if you parked in a garage (which you shouldn't do anyway). Most aftermarket kits also stick to this 10 or 15-minute limit.