Key Takeaways: Why Your Jeep Won't Start
- The Hood Switch: This is the #1 culprit. If the hood isn't latched tight or the sensor is bent, remote start is disabled.
- Check Engine Light: If you have any warning light on the dash, the system cancels remote start to protect the engine.
- Low Fuel: If the low fuel light is on, the car wont waste gas remote starting.
- Battery Issues: Weak key fob battery or a dying main/auxiliary battery under the hood.
- Door/Gate Ajar: One of the doors or the swing gate isn't fully closed.
The Short Answer
If you're standing in the driveway pressing the button on your fob and getting nothing but a horn honk or flashing lights, here is the fix. Go check your hood latches. On the 2020 Jeep Wrangler (the JL model), the hood sensors are incredibly sensitive. Even if it looks closed, one of the side latches might be loose or the center safety latch switch is dirty. Open the hood and slam it shut firmly. If that doesn't work, check your dashboard for a Check Engine Light or a Low Fuel light. Both of those will automatically disable the remote start feature according to the owner's manual.
If that didn't fix it, don't worry. We're gonna go through every single possibility below.
Common Reasons Your 2020 Wrangler Remote Start Failed
Its frustrating when technology fails, especially when its freezing outside and you want a warm car, or its blazing hot and you want the AC running. I've been there with my own Jeep. The system is designed to be overly safe. If the computer thinks anything is wrong, it just says "nope" and refuses to start the engine.
Here is a detailed breakdown of what goes wrong and how you can fix it yourself without paying a dealer $150 to look at it.
1. The Hood Pin Switch (The Usual Suspect)
I cannot stress this enough-this is almost always the problem on the JL Wranglers. There is a safety switch located near the latch mechanism under the hood. Its job is to ensure the engine doesn't start while someone has their hands inside the engine bay working on it.
The problem is that the switch can get dirty, or the bracket can get slightly bent. If the connection isn't perfect, the Jeep thinks the hood is open.
The Fix:
- Pop the hood and lift it up.
- Locate the switch (usually near the front latch).
- Clean it off with a rag.
- Close the hood and push down firmly on the front center and re-latch the side latches.
- Try the remote start again.
Some forums suggest unplugging and replugging the harness for the hood sensor if cleaning it doesnt work. If the sensor is actually broken, you might see a message on your dashboard cluster saying "Hood Ajar" even when it's closed. That's a dead giveaway.
2. The Check Engine Light (CEL)
This is a safety feature. According to Jeep's logic, if the Check Engine Light is on, something is wrong with the engine or emissions system. Remote starting the car means nobody is in the driver's seat to watch the gauges. So, to prevent the engine from potentially blowing up or overheating without a driver knowing, the system disables remote start.
The Fix:
- Start the Jeep normally with the key (or push button).
- Look at the dash. Is the yellow engine outline light on?
- If yes, you need to find out why.
Pro Tip: Sometimes a CEL is caused by a loose gas cap. I know, it sounds stupid, but if your gas cap isn't clicked tight, the EVAP system detects a leak and throws a code. Tighten the cap and drive for a day or two; the light might go off on its own, and your remote start will come back.
3. Low Fuel Level
This one catches a lot of people off guard. If your fuel needle is in the red or the "Low Fuel" warning light is on, the remote start will not engage. The computer is smart enough to know that idling wastes gas, and it doesnt want to run the tank dry before you even get in the car.
The Fix: Go to the gas station. Once you fill up, the system resets immediately.
4. Door or Swing Gate Ajar
Jeep Wranglers are like giant Lego sets. The doors come off, the roof comes off, and things get rattled around on trails. Because the doors are removable, the electrical connectors (the ones you unplug to take the doors off) can sometimes wiggle loose.
Also, the rear swing gate (trunk) requires a firm close. If the computer senses that the driver door, passenger door, back doors, or the trunk is even slightly open, it wont start.
The Fix: Walk around the Jeep. Open and firmly close every single door and the rear gate. If you recently took your doors off and put them back on, check the electrical harness connector under the dashboard to make sure it's clicked in all the way.
5. The Dreaded Auxiliary Battery
Okay, we need to talk about the batteries. The 2020 Wrangler (and most JLs) uses a dual-battery system for the ESS (Electronic Start/Stop) feature. There is the big main battery you can see, and a smaller, annoying "auxiliary" battery buried underneath the fuse box.
When the Aux battery starts to die, it causes all sorts of electrical gremlins. One of the first symptoms is the remote start stops working. You might also see a message on the dash that says "Start/Stop Not Ready: Battery Charging."
The Fix: This is harder to test without tools. But if your auto start/stop feature (where the engine turns off at red lights) hasn't been working lately either, your Aux battery is probably toast. You might need to replace it. A lot of Jeep owners bypass this battery entirely, but that's a more advanced modification.
6. Key Fob Battery is Low
Sometimes the problem isn't the car, it's the remote. If the battery inside your fob is weak, it might have enough juice to unlock the doors from close range but not enough to send the strong, sustained signal needed for remote start.
How to change the 2020 Jeep Key Fob Battery:
- Look for the mechanical key release button on the side of the fob and pull the metal key out.
- Use a flathead screwdriver or the tip of the key to pry the two halves of the plastic case apart. Don't be afraid to use a little force, but be gentle so you don't crack the plastic.
- Remove the old battery. It is usually a CR2450 coin battery.
- Put the new one in (make sure the positive side is facing the right way).
- Snap the case back together.
Weaker Signals and Interference
Did you know that where you park matters? I had a friend who couldn't get his Jeep to remote start at his office, but it worked fine at home. Turns out, he was parking near a high-power radio tower or some heavy electrical equipment.
RF (Radio Frequency) interference can block the signal from your fob to the Jeep. Also, the range on these things is decent, but not infinite. If you are too far away, or if there are concrete walls between you and the Jeep, it might receive the "lock" signal but miss the "start" signal.
The "Double Press" Technique
Just a reminder on how to use it properly, because sometimes we just forget. To remote start the 2020 Wrangler, you usually have to press the remote start button (the x2 circle arrow) twice within 5 seconds.
If you press it once, nothing happens. If you press it three times, it might start and then immediately shut off. It's all about the timing. Click-click. Not too fast, not too slow.
Check Your Uconnect Settings
If you recently had your battery disconnected or got a software update from the dealership, your settings might have reverted to default. The Uconnect system allows you to toggle remote start options.
How to check:
- Sit in the driver's seat and turn the car on.
- Tap the Settings gear icon on your touchscreen.
- Scroll down to Doors & Locks or Safety & Driving Assistance (it varies slightly depending on your software version).
- Look for "Remote Start System".
- Make sure the box is checked or toggled to "On".
- You can also look for "Remote Start Comfort Systems" to tell the Jeep if you want it to turn on the heated seats/steering wheel automatically.
When to Call the Dealership
If you have gone through this entire list-hood is shut, gas is full, no check engine lights, new batteries in the fob-and it still won't work, you might have a deeper issue.
There is a module called the RF Hub. On some 2020 models, these hubs had glitches. Sometimes they just need a software update (re-flash) that only the dealer can do. Other times, the module itself has failed.
Also, check if your Jeep is in "Valet Mode" or "Shipping Mode." This is rare for a 2020 model that you've been driving for a while, but if you just bought it used, the previous owner might have messed with the settings or installed an aftermarket alarm that is interfering with the factory system.
Frequently Asked Questions
Why does my Jeep honk but not start?
If it honks once or flashes the lights but doesn't crank, the computer is rejecting the request. This usually points to a "lockout" condition like a door ajar, hood open, or hazard lights being on. Listen closely-sometimes the horn chirp pattern tells you the error code (check your manual for the chirp codes).
How long will the Jeep run on remote start?
It will run for 15 minutes. After 15 minutes, it shuts off to save gas. You can usually extend it for another 15 minutes by doing the remote start sequence again, but you can only do this twice. After two cycles, you have to physically get in the car and push the start button to reset the timer.
Will remote start turn on my heated seats?
Yes, but you have to enable it! Go into your Uconnect settings under "Auto-On Comfort." You can set it so that if the outside temperature is below 40 degrees, the heated seats and steering wheel kick on automatically. It's a lifesaver in the winter.
Does the 2020 Jeep Wrangler have a remote start app?
Yes, if you have the Uconnect subscription. You can use the Jeep app on your smartphone to start the car from virtually anywhere (as long as the car has cell service). However, this is a paid subscription service after the trial period ends.
Can I add remote start if my Jeep didn't come with it?
Absolutely. You can buy the OEM kit from Mopar, or you can get aftermarket kits like Start-X or Compustar. The aftermarket ones are actually pretty easy to install-many of them are "plug and play" into the OBD2 port under the steering wheel and use your existing key fob (usually by pressing Lock 3 times).
Hopefully, this gets you back on the road with a warm (or cool) Jeep. 9 times out of 10, it's that hood latch or the fuel level. Give those a check and you should be good to go!