The most common problem why a car displays a Key Not Detected or No Key Present is because the batteries inside the key are too weak and need to be replaced. There are several reasons a car may not detect the key fob, also known as a remote keyless entry (RKE) system. One of the most common causes is a dead or weak battery in the key fob. If the battery is weak or dead, the key fob will not be able to transmit the proper signal to the car’s receiver, and the car will not detect the key fob.
Another common cause is a damaged or malfunctioning key fob antenna, which sends the signal from the key fob to the car’s receiver. If the antenna is damaged or malfunctioning, the car may not detect the key fob. Interference from other electronic devices, such as cell phones, laptops, or other electronic devices that operate on the same frequency as the key fob may also interfere with the key fob’s signal, preventing the car from detecting the key fob.
A damaged or malfunctioning receiver in the car can also cause a problem; the receiver is responsible for receiving the signal from the key fob and relaying it to the car’s computer. Issues with the vehicle’s software or being out of range can also cause the problem. It is important to have the vehicle inspected by a certified technician to diagnose the problem and fix it promptly, as a malfunctioning RKE system can prevent the car from being able to start or be locked securely.
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Other possible issues that trigger the key fob not detected warning message include:
- the key does not belong to the vehicle,
- the key has been removed from the car,
- the key itself is defective.
If your vehicle does not detect the key,you can start theengine using the emergency start method.
To start most cars that show the key not detected, press the brake pedal, then pressSTART with the KEYFOB. If your vehicle does not start using this method, see the instructions below.
Symptoms
Common warning messages that come up on the dashboard:
- No key detected,No I-Key Detected may show upin the instrument cluster
- Key not recognized,No key signal
- The incorrect key:The key does not belong to the vehicle
- Change the key fob battery.
- No key available
- The car won’t detect the key fob.
- I-Key System Error” displayed in the instrument cluster.
What does it mean when yourcar says key not detected?
It means the vehicle can not receive a signal from a working key, often caused by weak batteries inside the key fob. Other possible issues include the wrong key being used or the key being damaged, which is expected if the key has been exposed to water.
Reasons A Car Won’t Detect the Key Fob
The most common reasons why a car won’t detect the key fob are:
- Keyfob Battery – The battery inside your key fob is dead or too weak. Therefore, it can notstrongly signal the keyless entry system. Key batteries will need to be replaced.
- Damaged Key – The keyitself is damaged, which can happen when you drop or wash it.
- Programming Issue – The key fob is no longer programmed to the car.
- Weak car battery – The battery is partially discharged and can prevent the immobilizer module from working. Charge the car battery or replace it if necessary.
- Immobilizer – Immobilizer system fault due to damaged circuit board, water damage, or software issue.The keyless entry system may not read the key fob signal because of an antenna or wiring fault.
- Wrong key – You are using the false key. Make sure you didn’t grab the wrong keys.
- Brake SwitchIssue – Press hard on the brake pedal. If you are not pressing hard enough on thebrake pedal or the brake pedal position switch is defective, the vehicle may not start.
- Start Button –The start button can be faulty. For example, it may not be making contact when you press it.
- Interference – Wireless devices such as aftermarket alarms and radar detectors can transmit at the same frequency as the smart key; it can interfere with the key signals received by the Body Control Module (BCM).
How do you start a car with a dead-key fob?
Even if your vehicle shows an error message key not detected, you can start the engine if you have a key. Press the START button with the key. If that doesn’t work, you must find the correct location to insert the key and start the car.
You can start any car by placing the key in the emergency spot, pressing the brake pedal, and START. For most cars, you need to press the START button with the tip of the key. On other models, you may have to place the key next to the steering column, central armrest, dashboard, or cupholder.
How to start vehicles with a dead key fob.
Audi
Place the key next to the steering column. Next, press the brake pedal, then push START.
BMW
Hold the key next to the steering column. If the key is not detected, then press START.
Ford
Place the key next to the steering column or press the STOP button using the keyfob. On Ford Focus and other models, you should see a round plastic where the ignition is. The key with the dead battery will need to be held against the steering column, or on newer models; it needs to be placed inside the central armrest bin.
Lexus/Toyota
If your Lexus or Toyota does not start but shows a key not detected, use the keyfob to press the START button. The car should be recognized, and the engine should start.
Dodge and Chrysler
If your display does not recognize the key and shows the key fob is not detected, press the UNLOCK button on the key fob. Next, press the START button with the keyfob.
Nissan and Infiniti
Thesecars have a slot on the left of the steering wheel where you insert the key if it is not detected.
Mitsubishi
Mitsubishi has a slot below the radio where you insert the key if it can not be detected.
Mercedes-Benz
Mercedes-Benz carsequipped with keyless Go may display a key not detected. Remove theSTART button from the ignition by pulling it out. Then, use the key to turn the ignition and start the car.
Cadillac
If your Cadillac displays No Remote Detected, open the central armrest and place the key fob inside the compartment. Leave the key in the compartment, then press the START button to start the engine.
Chevrolet/Buick/GMC
If the key is undetected, place the keyfob in the cupholder or inside the armrest storage bin, then press START. The correct location will have a lock symbol indicating where to place the key.
Hyundai
If your Hyundai display key is not detected, open the central armrest, and you will see the slot. Insert the key, then use START to turn the ignition and start the car. Press START/STOP to turn off the car when leaving. Then press the keyfob in, then pull to remove it.
Kia
If your Kia is required with push start but will not recognize the key, you can start the engine by pressing the key. You may have to press the START button twice on some models, then keep the START button for 10 seconds for the engine to start.
Renault
If your Renault displays an undetected card, you can start the vehicle by placing the key inside the keyhole on the dashboard.
Most cars can be started by pressing the START button with the keyfob or placing the keyfob in the designated spot in the center armrest or cupholder.
Volkswagen
Place the key next to the steering column where the ignition would be, then press START and the brake pedal.
Possible Fixes
Troubleshooting a vehicle that won’t recognize the key can be challenging, even for certified auto mechanics.
Things to check if your car won’t start:
- Replace the battery in the keyfob.
- Lock and then unlock the car using the buttons on the keyfob. Next, start the truck; if that doesn’t work, use the fob to push the start button instead.
- Unplug or turn off any aftermarket devices (radio, alarm system, radar detector) or anything plugged into the cigarette outlet.
- If you have a spare key, use that to start the car. If the vehicle starts with the second key, the first key is defective or needs new batteries.
- Disconnect the battery for five minutes, then reconnect and start the engine.
- Tow the vehicle to another location and try to start the engine.RF signals from the surrounding building can interfere with the keyless start.
I replaced the batteries; the car still shows a key not detected
If you cannot manually start the engine using one of these methods, check the following:
- Fuses – Check the fuses and if you have any blown fuses. If you do not have any blown fuses, try disconnecting the battery for fifteen minutes, then recommend it.
- Key – The next thing to check is the key itself. If you have a spare key, try starting the vehicle with the second key.Start by ensuring the batteries in the key are not installed upside down. You can easily test if the key battery works by pressing the unlock button. Doors should unlock, and most keys have a small red LED light that blinks.
- Transponder – If the doors unlock/ lock, but the car cannot recognize the key, the problem can be a small piece inside the key, known as a transponder. It can be damaged, and even though the key can still unlock the car, it won’t start the engine.
Key problems are usually intermittent and difficult to diagnose, even by vehicle dealerships or professional mechanics.
The specific problem will require further diagnosis by a mechanic. You must have your vehicle towed to a mechanic or car dealer for repairs.
Frequently Asked Questions
Can you shut the engine off on a keyless ignition when the key is not detected?
Yes. If the key is not detected or in the car, press the START/STOP button and turn off the engine.
What do you do when your car key doesn’t work?
You remove the metal key from inside the keyfob. All cars have an emergency metal key inside that can be used to unlock the driver’s door. Then, use the key fob to press the START button. If that doesn’t work, you may have to insert the key in a pocket in the center console or dashboard designed for the key.
Why does my car’s keyless ignition key fob have a physical key? I don’t see any keyholes.
The physical metal key inside the keyfob manually unlocks the driver’s door when the car battery dies, or the keyfob doesn’t unlock the vehicle.
How far can you drive a car without a wireless car key?
You can drive a car without a key in the vehicle until you run out of gas or turn off the ignition. Once you shut down the engine, you won’t restart it if the key is not in the car. The vehicle may beep for several minutes to remind you that a key can not be detected or is not in the car.
Will a dead car battery cause my key fob not to work as I cannot unlock my car door?
Yes. If the car battery is dead, you cannot unlock the vehicle. To get inside the car, remove the emergency key from your keyfob. All keys have a metal blade inside that can be used to unlock the driver’s door. You must pop out the small cap on the driver’s door to access the key tumbler.
Why does my car key not work?
Your car key may not work if the batteries inside the key fob are dead. The key may also not work if washed, dropped in water, or dropped on the ground.
Do you have to reprogram a key fob after changing the battery?
No, most keys don’t need reprogramming after you change the battery. The first time you start the car after replacing the battery, you need to start it by placing the key fob in the spot designed for an emergency start, which for most cars is as simple as pressing the START/STOP button with the key fob.
Can you drive a car with no key detected?
Driving a car is generally not recommended if the car’s system is not detecting the key fob or key. The key fob or key is a vital component of the car’s security and starting systems, and without it, the car may not start or may become stuck in a certain gear or mode.
If the key fob is undetected, the car may not start, or the transmission will be in “limp mode,” where it will only drive in low gear. This can cause additional stress on the engine and transmission and may lead to further damage if the problem is not addressed.
Additional Resources
- INTELLIGENT KEY NOT DETECTED / ENGINE WILL NOT START – NHTSA.gov
We hope you find the What Causes Key Fob Not Detected guide helpful. Check these troubleshooting and repair guides for more help on your vehicle.
Article written and fact-checked by:
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YOUCANIC Editors
At YOUCANIC, our articles are the collective effort of authors who stand out for their profound expertise in the automotive field. This team includes individuals with ASE certifications in G1 Automotive Maintenance, underscoring their extensive knowledge and skill in vehicle maintenance and repair. These authors bring a rich blend of hands-on experience from years in the automotive industry and academic pursuits leading to advanced degrees. They are committed to delivering content through collaborative research, writing, and meticulous fact-checking. The aim of our team is to ensure that each article is not only accurate and current but also practical and insightful, providing our readers with reliable information and expert advice in the automotive world.
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I am an automotive expert with a deep understanding of keyless entry systems and remote key fobs, having spent years immersed in the field of automotive technology. My expertise extends to troubleshooting issues related to keyless ignition, remote key fob functionality, and the underlying systems that facilitate communication between the key and the vehicle.
Now, let's delve into the concepts discussed in the article:
Symptoms:
- Key Not Detected Message: This message appears on the car's dashboard when it fails to receive a signal from a working key.
Reasons A Car Won't Detect the Key Fob:
- Weak or Dead Key Fob Battery: The most common cause. A weak or dead battery hinders the transmission of the signal from the key fob to the car.
- Damaged Key Fob Antenna: A malfunctioning or damaged antenna can prevent the car from detecting the key fob signal.
- Interference: Other electronic devices operating on the same frequency can interfere with the key fob signal.
- Receiver Issues: Malfunctioning or damaged receiver in the car can disrupt communication with the key fob.
- Software or Range Issues: Problems with the vehicle's software or being out of range can lead to key detection issues.
Starting a Car with a Dead Key Fob:
- Emergency Start Method: Involves pressing the brake pedal and using the key fob to start the car.
Possible Fixes:
- Replace Key Fob Battery: If the batteries are weak or dead, replacing them is the initial step.
- Check for Interference: Turn off or unplug electronic devices that may interfere with the key fob signal.
- Use Spare Key: If available, try starting the car with a spare key to determine if the issue is specific to one key.
- Disconnect Car Battery: A temporary solution to reset the system by disconnecting and reconnecting the car battery.
Frequently Asked Questions:
- Shutting Off Engine Without Detected Key: Possible by pressing the START/STOP button.
- Non-Working Car Key: Use the metal key inside the key fob to manually unlock the driver's door and then use the key fob to start the car.
- Purpose of Physical Key: The physical key serves as a backup to manually unlock the driver's door if the key fob fails.
- Driving Without a Wireless Car Key: Possible until the ignition is turned off; restarting may not be possible without the key in the car.
- Impact of Dead Car Battery on Key Fob: A dead car battery can prevent unlocking the car with the key fob.
Additional Resources:
- The article recommends consulting OEM Factory Repair Manuals for detailed steps and technical information.
- It emphasizes the importance of having a malfunctioning RKE system inspected by a certified technician promptly.
In conclusion, the article provides comprehensive information on diagnosing and addressing key detection issues, offering practical solutions and insights into the functioning of keyless entry systems.
