What Causes Key Fob Not Detected

Contents

The most common problem why a car displays Key Not Detected or No Key Present is because the batteries inside the key are too weak and need to be replaced.

Other possible issues that trigger key fob not detected warning message include:

  • the key does not belong to the vehicle,
  • the key has been removed from the vehicle, 
  • the key itself is defective. 

If your vehicle does not detect the key, you can start the engine using the emergency start method. 

Key Not Detected Fix

To start most cars that show key not detected, press the brake pedal, then press START with the KEYFOB.

If your vehicle does not start using this method, see the instructions below. 

Symptoms

Key Not Detected

Common warning messages that come up on the dashboard: 

  • No key detected, No I-Key Detected may show up in the instrument cluster
  • Key not recognized, No key signal
  • The incorrect key, Key does not belong to the vehicle
  • Change key fob battery 
  • No key available
  • Car won't detect key fob
  • I-Key System Error” displayed in the instrument cluster 

What does it mean when your car says key not detected? 

key not detected

It means that 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 is being used or the key is damaged, which is common if the key has been exposed to water. 

Common Causes

most common problem that causes key not detected is dead weak battery

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 not send a strong signal to the keyless entry system. Key batteries will need to be replaced.
  • Damaged Key - The key itself is damaged, which can happen when you drop the key or wash it. 
  • Programing Issue - The key fob is no longer programmed to the car.
  • Weak car battery - The car 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 be reading the signal from the key fob because of an antenna or wiring fault.
  • Wrong key - You are using the wrong key. Make sure you didn't grab the wrong keys. 
  • Brake Switch Issue - Press hard on the brake pedal. If you are not pressing hard enough on the brake 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, radar detectors can transmit at the same frequency as the smart key; it can interfere with the key signals being received by the Body Control Module (BCM). 

How do you start a car with a dead-key fob? 

Dodge Chrysler Key Not Detected

Even if your vehicle shows an error message key not detected, you can start the engine as long as you have a key present. Press the START button with the key. If that doesn't work, you need to 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. You may have to place the key next to the steering column, central armrest, dashboard, or cupholder on other models.

How to start vehicles with a dead key fob. 

Audi 

Start Audi key not detected

Place the ky next to the steering column. Next, press the brake pedal, then push START. 

BMW

BMW key not detected

If the key is not detected, hold the key next to the steering column, 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 

Start Lexus key not detected

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 recognize, and the engine should start. 

Dodge and Chrysler

If your display does not recognize the key and shows the key fob not detected, first press UNLOCK button on the key fob. Next, press the START button with the keyfob. 

Nissan and Infiniti

These cars have a slot on the left of the steering wheel where you insert the key if it is not detected. 

Mitsubishi 

How to start mitsubishi key not detected

Mitsubishi has a slot below the radio where you insert the key if it can not be detected. 

Mercedes-Benz 

How to start Mercedes shows key not detected

Mercedes-Benz cars equipped with keyless go may display key not detected. Remove the START 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 not detected, place the keyfob in the cupholder or inside the armrest storage bin, then press START. The correct location will have a lock symbol indicating that that is 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 in the slot, then use START to turn on the ignition and start the car. When you leave the vehicle, press START/STOP to turn off the vehicle. 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 a card not detected, a card not detected 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 by placing the keyfob in the designated spot in the center armrest or cupholder. 

Volkswagen

start volkswagen with dead key fob battery

 

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 then unlock the car using the buttons on the keyfob.  Next, try to 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 5 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 key not detected 

Key Not Detected cause

If you cannot manually start the engine using one of these methods, check the following:

  1. Fuses - Check the fuses and if you have any blown fuses. If you do not have any blown fuses, try disconnecting the battery for 15 minutes, then recommend. 
  2. 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 unlock button. Doors should unlock, and most keys have a small red LED light that blinks. 
  3. Transponder - If the doors unlock/ lock, but the key can not be recognized by the car, 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 can be very difficult to diagnose even by vehicle dealerships or professional mechanics.  

The certain problem will require further diagnosis by a mechanic. You will have to 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 is not in the car, you can 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 in it? I don't see any keyholes?

  • The physical metal key inside the keyfob is used to manually unlock the driver's door when the car battery dies, or the keyfob doesn't work to 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 the engine if the key is not in the car.  The vehicle may beep for serval minutes to remind you that a key can not be detected or is not present in the vehicle. 

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 will not be able to 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. On the driver's door, you need to pop out the small-cap 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 it has been 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 keyfob 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. 

Additional Resources

  1. INTELLIGENT KEY NOT DETECTED / ENGINE WILL NOT START  - NHTSA.gov
What Causes Key Fob Not Detected The most common problem why a car displays Key Not Detected or No Key Present is because the batteries inside the key are too weak and need to be replaced. Other possible issues that trigger key fob not detected warning message include: