Key System Error Nissan Altima: Fixes For 2019

Although Nissan makes reliable cars, sometimes they experience problems, like all automakers. The Altima often displays a message that reads ‘key system error’.

Key System Error Nissan Altima Fixes For 2019

Based on my experience as an auto technician, this article explains what this problem is and how it can be fixed.

Key System Error Nissan Altima

“Key System Error” indicates that your Nissan Altima’s immobilizer system is not able to communicate with your Nissan’s system.

A key fob has a hard time being recognized by most vehicles.

Key System Error Nissan Altima

Intelligent Keys are used by Nissan. You will usually not be able to start your Altima when this fault message appears, but you can lock and unlock it.

Let’s take a look at the main causes of Nissan’s key system faults now that you know what it means.

Nissan Altima Key System Error: Causes

Nissan Altima Key System Error Causes

Key fob battery is dead

Key System Errors are typically caused by your key fob’s battery.

If you use your Nissan key fob frequently, the battery is known to fail frequently.

Most auto parts stores or Nisan dealerships sell replacement batteries for this battery, so you won’t have any problems finding one.

As far as I know, keyfob batteries last between three and five years before they need to be replaced.

Antenna Issues

Your Intelligent Key is detected by the antenna, which allows you to lock and unlock doors and start your car.

After changing dead batteries in your key fob, if you still have issues starting your car or the warning light stays illuminated, you may have an antenna problem.

Over time, your existing antenna may have been damaged by water or wear and tear. See if there are any visible signs of damage.

Antenna Issues

Your Intelligent Key transmits a signal to the antenna, allowing you to unlock doors, start your car, and much more.

After replacing dead batteries in your key fob and still experiencing problems starting your car, your antenna may be malfunctioning.

Over time, your existing antenna may have been damaged by water or wear and tear. Make sure there are no visible signs of damage.

A car immobilizer, however, disables the engine if an incorrect or unrecognized key is detected, preventing unauthorized access. In the event of either of these systems malfunctioning, you may encounter difficulties starting your vehicle.

Intelligent Nissan Key Fob Malfunction

The Key System Error may still appear on your dashboard if you have recently replaced your key fob battery. Almost any Nissan dealership can program your Nissan Intelligent key fob for you.

There are many reasons why Nissan Keyfobs can malfunction, including software issues and keyfob damage from dropping it. The Intelligent Key System must be reprogrammed to resolve this issue.

Nissan Altima Key System error: Diagnosing And Fixing

Change Key Fob Battery

Changing the keyfob battery is the first step. Your local Nissan dealership or auto parts store can provide the Nissan Altima battery you need.

Change Key Fob Battery

Fortunately, they are not too expensive. Batteries for keyfobs should cost between $5 and $10. Watch the video below to learn how to replace your Altimas keyfob’s battery.

Reprogram the Keyfob

You will need to reprogramme the key fob if the problem persists. Nissan dealerships can reprogram your key fob and car by taking them to their facilities.

Reprogram the Keyfob

When you consider how much money these things cost when they go bad, it’s worth it to spend $100-200 on this.

These fixes should get your key fob working again, but if you still cannot, your car may be malfunctioning. Various problems can cause this, from a bad battery connection to a malfunctioning ignition switch.

However, “Key system error” is caused by a bad keyfob battery or a malfunctioning fob that needs reprogramming 99% of the time.

Using A Spare Key

It is possible to diagnose a key system error issue by using a spare key in order to determine whether it is a specific key issue or a more general issue with the system. The process is as follows:

Using A Spare Key
  • 1. Use your spare key to begin the car.
  • 2. If you can start the car with the spare key, you know the problem is specific to the key and not the system as a whole.
  • 3. If neither key starts the car, there might be a more severe problem that requires professional attention.
  • 4. The main electronic key fob can continue to be used if both keys work fine and the vehicle starts and runs smoothly.

When your main electronic key fob gets damaged or lost, it’s always a good idea to have a spare key handy. It is also important to check and maintain your keys’ batteries regularly to prevent such problems.

Contacting a Nissan dealer or a car locksmith

If this is the case, you need to get it fixed as soon as possible by visiting a Nissan dealership or a car locksmith.
An automotive technician at a Nissan dealership can conduct diagnostic tests to determine the problem’s cause. Your keys may need to be reprogrammed or parts may need to be replaced.

Contacting a Nissan dealer or a car locksmith

In addition to dealerships, a locksmith may provide similar services at a lower cost. To ensure the best service, check their reviews before you pick someone.

How can you prevent the Key System Error from occurring?

A key fob’s battery should be checked regularly, and extreme temperatures and water damage should be avoided.

How can you prevent the Key System Error from occurring

Regular Maintenance Checks

Preventing malfunctions with your car requires regular maintenance. In addition to having the vehicle serviced regularly, you should have the antenna and key fob batteries checked by a professional mechanic, as recommended by the manufacturer.

As well, I recommend reading through the owner’s manual to learn everything you need to know about avoiding key system errors. Car owners’ manuals usually contain specific instructions on how to maintain and care for their keys.

Battery Replacement

Specialists recommend replacing the key fob’s batteries every 3-4 years to prevent dead batteries. In addition, if you obtain a new key, make sure you program it as per your owner’s manual.

Water Damage and Extreme Temperatures

Preventing water damage and extreme temperatures will extend the life of your key.
Battery life and car security systems can be negatively affected by extreme temperatures.

Make sure your keys are not placed near electronics that generate heat or in direct sunlight to avoid these problems. Swimmers or water sports participants should avoid taking them with them.

How Long Does Nissan Altima Key Fob Last?

Key fob batteries typically last about three years, depending on how much use they receive.

Depending on how much you use them, I have found they can last anywhere between 5 and 10 years. Those who seldom use their key fobs will have a longer battery life than those who frequently use them for locking doors and starting cars.

Key System Error Nissan Altima Resetting Process

  • The first thing you should do is lock the door of your car.
  • The key should be inserted and removed several times from the ignition. By doing this, the program mode will be activated.
  • Rotate the ignition key after inserting it into the ignition. To activate the intelligent key, press the button.
  • Take a look at the key fob now. The Nissan Altima key has been reprogrammed properly if it flashes or beeps.

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Frequently Asked Questions

Is it possible for my Nissan Altima to be completely immobilized if the key system fails?

Yes, sometimes. It is possible to resolve many key errors with proper troubleshooting, however.

Is it common for Nissan Altima electronic keys to malfunction?

Electronic keys can malfunction for a variety of reasons, although they aren’t very common. By maintaining these systems regularly, these problems can be mitigated.

Can I still drive my Nissan Altima if there is a Key System Error?

With a Key System Error, you can still drive, but your keyless entry system may not work properly when you attempt to start your car or unlock it.

What should I do if my key fob is unresponsive?

Check the key battery first. The owner’s manual will provide specific steps for troubleshooting if the issue persists.

How can I get key system updates?

For optimal performance and security, updates are essential. Check the official Nissan website or your local Nissan dealership for updates.

Do DIY troubleshooting methods void my warranty?

Checking the battery in your key won’t void your warranty in most cases. Professionals are recommended for major issues.


To resolve Nissan Altima’s key system errors, it is imperative to understand the potential causes, recognize the signs, and implement effective troubleshooting techniques. The best way to avoid these issues is to maintain the equipment regularly, be aware of manufacturer updates, and stay up-to-date on all manufacturer updates.

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