Smart Entry And Start System Malfunction in Toyota Vehicles

smart entry and start system malfunction

Toyota vehicles equipped with a smart key system offer convenience and ease of use. However, like any advanced technology, the smart key system can experience malfunctions that may prevent you from starting your car or using other smart key features.

In this guide, we will explore the causes of smart key system malfunctions, how to troubleshoot and fix them, and preventive measures to avoid future issues.

So let’s dive in and unravel the mysteries behind smart key system malfunctions in Toyota vehicles.

What Does a Smart Key System Malfunction Mean?

If you’ve ever seen the “smart key system malfunction” error message displayed on your Toyota’s dashboard, you may be wondering what it means and how it will affect your vehicle. Essentially, a smart key system malfunction indicates that your Toyota’s smart key is not functioning properly.

This can result in the inability to start your car normally or utilize other smart key features. The error message usually appears in the center of the dashboard display and may flash when you attempt to start your vehicle.

Common Causes of Smart Key System Malfunctions

Understanding the potential causes of smart key system malfunctions can help you diagnose and resolve the issue more effectively.

While there can be various factors contributing to a smart key malfunction, one common scenario is a dead car battery. Here are some possible causes of smart key system malfunctions:

  1. Dead Car Battery: Leaving electronics, such as interior lights, accidentally turned on overnight can drain the car battery. Additionally, an old or faulty battery that cannot hold its charge, especially in cold weather, may contribute to a smart key system malfunction. In some cases, an electronic glitch within the car’s system can also cause excess power consumption, leading to a drained battery.
  2. Smart Key Battery: If the battery in your smart key is dead or low, it may not communicate properly with the vehicle, resulting in a smart key system malfunction. Regularly replacing the smart key battery can help prevent this issue.
  3. Computer System Malfunction: Occasionally, a malfunction in the car’s computer system can disrupt the communication between the smart key and the vehicle, leading to a smart key system malfunction.

Troubleshooting and Fixing Smart Key System Malfunctions

When faced with a smart key system malfunction, there are several steps you can take to troubleshoot and resolve the issue. Let’s explore some potential solutions based on the causes mentioned earlier:

1. Jump-Start Your Vehicle’s Battery

If you suspect that a dead car battery is causing the smart key system malfunction, jump-starting your vehicle’s battery can often resolve the issue. Here’s how to jump-start your car:

  1. Find another vehicle with a working battery.
  2. Connect the positive (red) jumper cable to the positive terminal of the dead battery.
  3. Connect the other end of the positive jumper cable to the positive terminal of the working battery.
  4. Connect the negative (black) jumper cable to the negative terminal of the working battery.
  5. Attach the other end of the negative jumper cable to a metal surface on the car with the dead battery, away from the battery itself.
  6. Start the vehicle with the working battery and let it run for a few minutes.
  7. Attempt to start your car. If successful, the smart key system malfunction should no longer appear.

2. Replace the Smart Key Battery

If jump-starting the car doesn’t resolve the smart key system malfunction, it may be due to a low or dead battery in the smart key itself. Follow these steps to replace the smart key battery:

  1. Locate the slot or button on your smart key that allows you to remove the key blade.
  2. Use the key blade to open the smart key case.
  3. Remove the old battery and replace it with a new one of the same type (check your vehicle’s manual for the appropriate battery model).
  4. Close the smart key case and reinsert the key blade.

3. Seek Professional Assistance

If jump-starting the car and replacing the smart key battery fail to resolve the issue, it’s recommended to consult a certified Toyota dealer or trusted mechanic.

They have the expertise and diagnostic tools to identify and fix any underlying computer system malfunctions or other complex issues causing the smart key system malfunction.

Read also >> Toyota Smart Key System Malfunction (Step by Step Solved!)

Driving Without the Smart Key

In some cases, you may need to drive your Toyota even if the smart key is not functioning correctly. Here’s what you can do:

  1. Unlock the car door manually using the physical key hidden within the smart key.
  2. If your Toyota is less than 15 years old, hold the smart key’s logo up to the “ENGINE START STOP” button.
  3. If your Toyota is more than 15 years old, press the deactivation switch located on the dashboard below the steering wheel.
  4. Remember to jump-start the car if the battery is dead before attempting to start the engine.

Benefits of the Smart Key System

Despite the occasional malfunctions, the smart key system in Toyota vehicles offers numerous benefits. It provides convenience by allowing you to unlock the doors without physically using the key and eliminates the need to remove the key from your pocket to start the car.

This is especially useful when your hands are full or during inclement weather. The smart key system recognizes when you have the key in your possession, making it effortless to start the vehicle with the push of a button.

Preventing Future Smart Key System Malfunctions

While some smart key system malfunctions may be unavoidable, there are preventive measures you can take to reduce the likelihood of encountering such issues. Here are some tips to help prevent future smart key system malfunctions:

  1. Turn Off Electronics: Whenever you park your car for an extended period, ensure that all electronics, such as interior lights, are turned off to prevent unnecessary battery drain.
  2. Keep Spare Key Fob Batteries: Have spare batteries for your smart key fob on hand. Regularly check and replace the batteries to ensure proper functioning.
  3. Park in a Safe Location: When parking your vehicle, choose safe locations where there is minimal risk of theft or damage. This reduces the chances of encountering smart key system malfunctions caused by external factors.

By following these preventive measures, you can minimize the likelihood of experiencing smart key system malfunctions and enjoy a smooth and hassle-free driving experience.


The smart key system in Toyota vehicles offers convenience and ease of use, but it can occasionally experience malfunctions. Understanding the causes of smart key system malfunctions, troubleshooting techniques, and preventive measures can help you address these issues effectively.

Remember to jump-start the car, replace the smart key battery, and seek professional assistance if necessary. By following these steps and taking preventive measures, you can ensure that your smart key system functions properly and enjoy the benefits it provides.

Drive safely and confidently with your Toyota’s smart key system!

Steve P.

Steve is an automotive technician, technical writer, and Managing Editor. He has held a lifelong passion for cars, with a particular interest in cars like the Buick Riviera. Steve is based in Boise, Idaho.

Recent Posts

error: Content is protected !!