How To Change Battery In Lexus Key Fob: A Step-by-Step Guide

Having a properly functioning key fob is essential for the seamless operation of your Lexus vehicle. This small but mighty device allows you to unlock doors, start the engine, and access other convenient features without ever taking the physical key out of your pocket or purse. However, like any battery-powered device, the key fob’s battery has a limited lifespan and will eventually need to be replaced.

How do you change the battery in a Lexus key fob?

To change the battery in a Lexus key fob, you’ll need a small flathead screwdriver and a new CR2032 lithium coin cell battery. After locating the release switch to remove the emergency key, use the screwdriver to gently pry open the key fob casing. Replace the old battery with the new one, ensuring the positive (+) side is facing up, and then reassemble the key fob.

This guide will walk you through the entire process step-by-step, as well as provide tips for identifying when your key fob battery needs replacing, extending its lifespan, troubleshooting issues, and finding the right replacement battery and key fobs.

Table of Contents

What is a Lexus Key Fob and Why is Changing its Battery Important?

A key fob, also known as a remote keyless entry device, is a small wireless remote control that comes with most modern vehicles, including Lexus models. It allows you to lock and unlock your car doors, open the trunk or liftgate, and even start the engine with the push of a button – all without having to physically insert a key into the door or ignition.

In addition to these basic functions, many Lexus key fobs also include additional features like remote engine start, panic alarm activation, and even personalized driver settings. The key fob communicates with your Lexus using radio frequency (RF) signals, which are powered by a small battery inside the fob.

Changing the key fob battery when it starts to run low is crucial for several reasons:

Convenience: A dead key fob battery means you’ll have to resort to manually unlocking and starting your Lexus, defeating the purpose of having a keyless entry system.
Security: Some Lexus models rely on the key fob for their engine immobilizer system, which prevents the vehicle from being started without the presence of a valid key fob signal. A dead battery could potentially leave your car vulnerable to theft.
Safety: Features like the panic alarm and remote engine start rely on a working key fob battery to function correctly.

Replacing the key fob battery is a simple and inexpensive task that can save you from the hassle and potential risks associated with a non-functioning key fob.

Signs Your Lexus Key Fob Battery Needs Replacing

Before you start the process of changing the battery, you’ll need to identify if your key fob is indeed running low on power. Here are some common signs that it’s time for a Lexus key fob battery replacement:

Decreased range: You have to move closer to your Lexus for the key fob to work when locking, unlocking, or starting the vehicle.
Dim or non-functioning LED light: The small LED light on the key fob doesn’t illuminate when you press a button, or it’s noticeably dimmer than usual.
Issues with push-button start or Smart Access: The engine doesn’t start when you press the start button, or the Smart Access system (which allows you to unlock the doors without pressing any buttons) is not working correctly.
Low battery warning: Some Lexus models will display a warning message on the dashboard or emit an audible alert when the key fob battery is running low.

If you notice any of these signs, it’s a good idea to replace the battery as soon as possible to avoid any inconvenience or potential security risks.

What Type of Battery Do Lexus Key Fobs Use?

Most Lexus key fobs use a CR2032 lithium coin cell battery, which is a widely available and inexpensive battery type. However, it’s essential to double-check the correct battery type for your specific Lexus model and year, as some older or less common models may use a different battery.

You can typically find the recommended battery type in your Lexus owner’s manual or by contacting your local Lexus dealership’s parts department. Providing them with your vehicle’s make, model, and year should allow them to look up the correct battery type for your key fob.

Using the wrong battery type or a low-quality, non-OEM (Original Equipment Manufacturer) battery can lead to poor performance, shortened battery life, or even potential damage to the key fob’s internal components. It’s always best to use the recommended battery type and brand specified by Lexus for your specific vehicle.

Step-by-Step Guide to Changing the Lexus Key Fob Battery

Now that you know the signs of a dying key fob battery and the correct replacement battery type for your Lexus, it’s time to learn how to change the battery yourself. Here’s a step-by-step guide that should work for most Lexus key fobs:

Tools Needed:

A small flathead screwdriver
A new CR2032 lithium coin cell battery (or the recommended battery type for your Lexus model)

Step 1: Remove the Mechanical Key

Most Lexus key fobs have a small, hidden mechanical key that can be used to manually unlock the doors in case of a dead battery or other emergency. Locate the release switch or button on the side of the key fob and slide or press it to remove the mechanical key.

Step 2: Open the Key Fob Casing

With the mechanical key removed, you should see a small indentation or slot where it was housed. Insert the tip of your flathead screwdriver into this opening and gently pry or twist to separate the two halves of the key fob casing.

Pro tip: To avoid scratching the key fob’s plastic casing, you can wrap the tip of the screwdriver with a small piece of tape or a thin cloth.

Step 3: Remove the Old Battery

Once the key fob casing is open, you should see the old battery nestled inside. Take note of which way the positive (+) side of the battery is facing, as you’ll need to install the new battery in the same orientation.

Use the flathead screwdriver or a non-metallic tool (to avoid potential short circuits) to gently pry the old battery out of its compartment.

Step 4: Insert the New Battery

With the old battery removed, grab your new CR2032 (or appropriate battery type) and insert it into the battery compartment with the positive (+) side facing upwards, following the same orientation as the old battery.

Ensure that the new battery is securely seated in the compartment and not sitting at an angle or misaligned.

Step 5: Reassemble the Key Fob

Once the new battery is in place, carefully realign the two halves of the key fob casing and press them together until they snap or click back into place.

After reassembling the key fob, reinsert the mechanical key into its slot or compartment.

Step 6: Test the Key Fob

With the new battery installed and the key fob reassembled, it’s time to test its functionality. Press the lock, unlock, or panic buttons to ensure that the key fob is communicating with your Lexus and that all buttons are working correctly.

If the key fob is still not functioning properly after replacing the battery, there may be an issue with the internal components or the key fob programming. In this case, it’s best to consult with a Lexus dealership or an automotive locksmith for further assistance.

Tips for Specific Lexus Key Fob Designs

While the basic process of changing the battery is similar across most Lexus key fobs, some models may have slightly different designs or mechanisms for accessing the battery compartment. Here are a few tips for some common key fob variations:

Key Fobs with Screws

Some Lexus key fobs may have one or more small screws holding the casing together instead of a snap-fit design. In this case, you’ll need a precision screwdriver (typically a Phillips or Torx head) to remove the screws before prying the casing apart.

Key Fobs with Coin Slots

Certain key fob designs may have a small slot or indentation labeled “Coin Open” or a similar instruction. For these, you’ll need to insert a flat object like a coin or a flat-bladed screwdriver into the slot and twist to separate the casing halves.

Key Fobs with Electronic Key Modules

Some higher-end Lexus models may have an additional electronic key module or circuit board covering the battery compartment. In these cases, you’ll need to carefully remove this module before accessing the battery, taking note of its orientation for reassembly.

Key Fobs with Electronic Key Modules

After removing the electronic key module, you can proceed with steps 3 and 4 to remove the old battery and insert the new one. When reassembling the key fob, ensure that the electronic key module is properly realigned and securely seated before snapping the casing back together.

If you’re unsure about the specific design or components of your Lexus key fob, it’s always a good idea to consult your owner’s manual or reach out to a Lexus dealership for guidance. They can provide model-specific instructions and ensure that you don’t inadvertently damage any internal components during the battery replacement process.

Extending Your Lexus Key Fob Battery Life

While key fob batteries typically last between one and two years with regular use, there are a few steps you can take to help extend their lifespan and reduce the frequency of replacements:

Activate Battery-Saving Mode

Many Lexus key fobs have a built-in battery-saving mode that can be activated when the key fob is not in use for an extended period. This mode essentially puts the key fob into a low-power state, reducing the drain on the battery.

To activate the battery-saving mode, follow these steps:

Hold down the “LOCK” button on the key fob.
While still holding the “LOCK” button, press the “UNLOCK” button twice.
The key fob’s LED light should flash four times, indicating that the battery-saving mode has been activated.

To exit the battery-saving mode and resume normal operation, simply press any button on the key fob.

Keep Away from Magnetic Fields and Electronics

Magnetic fields and electromagnetic radiation from household electronics like TVs, laptops, and wireless routers can interfere with the key fob’s signal and cause it to drain its battery faster. To avoid this, try to keep your Lexus key fob at least three feet away from these types of devices when not in use.

Use OEM Batteries

While it may be tempting to save a few dollars by purchasing generic or off-brand replacement batteries, these can sometimes have shorter lifespans or lower quality compared to genuine Lexus OEM (Original Equipment Manufacturer) batteries. Using the recommended OEM battery can help ensure optimal performance and longevity for your key fob.

Troubleshooting a Non-Working Key Fob After Battery Change

In some cases, even after correctly replacing the battery, you may find that your Lexus key fob is still not functioning properly. If this happens, here are a few troubleshooting steps you can take:

Double-Check Battery Installation

Ensure that the new battery is correctly installed with the positive (+) side facing upwards and that it’s securely seated in the battery compartment. A misaligned or loose battery can prevent proper electrical contact and cause the key fob to malfunction.

Check for Moisture Damage

If any moisture got inside the key fob casing during the battery replacement process, it could potentially cause corrosion or short circuits. Carefully inspect the interior of the key fob for any signs of moisture or corrosion and allow it to fully dry out before reassembling.

Reset or Reprogram the Key Fob

In some cases, the key fob may need to be reset or reprogrammed to re-establish communication with your Lexus after a battery change. This process can vary depending on your specific Lexus model, so it’s best to consult your owner’s manual or contact a Lexus dealership for guidance.

Consider Professional Assistance

If you’ve tried all of the above troubleshooting steps and your key fob still isn’t working correctly, it’s time to seek professional assistance. A Lexus dealership or an experienced automotive locksmith can diagnose and address any underlying issues with the key fob or its programming.

Where to Get Replacement Batteries and Key Fobs

When it comes time to replace the battery or, in some cases, the entire key fob itself, you have a few options:

Lexus Dealerships

Your local Lexus dealership’s parts department is the most straightforward source for genuine OEM replacement batteries and key fobs. While this option may be more expensive than third-party sources, you can be assured that you’re getting a high-quality, Lexus-approved part that’s specifically designed for your vehicle.

Auto Parts Stores

Many national auto parts store chains like AutoZone, Advance Auto Parts, and NAPA carry a selection of replacement key fob batteries and, in some cases, aftermarket key fobs for various makes and models. However, it’s essential to verify compatibility with your specific Lexus before making a purchase.

Online Retailers

There are numerous online retailers that specialize in replacement key fobs, batteries, and other automotive accessories. These can be a more affordable option, but be sure to research the seller’s reputation and product quality before making a purchase.

Locksmiths and Mobile Key Services

In addition to traditional brick-and-mortar locksmiths, there are also mobile key service providers that can cut and program new key fobs for your Lexus right at your location. While often more expensive than DIY options, these services can be convenient if you need a replacement key fob quickly.

Regardless of where you source your replacement battery or key fob, it’s always a good idea to double-check compatibility with your specific Lexus model and year to ensure proper fit and function.

Cost of Replacing a Lexus Key Fob Battery

One of the benefits of changing the key fob battery yourself is the relatively low cost compared to having it done at a Lexus dealership or locksmith. Here’s a breakdown of the typical costs involved:

DIY Battery Replacement

Replacement CR2032 battery: $2 – $5
Total DIY cost: $2 – $5

Dealership Battery Replacement

Replacement OEM battery: $5 – $10
Labor cost: $10 – $30
Total dealership cost: $15 – $40

As you can see, the DIY approach can save you a significant amount of money, especially if you plan on replacing the battery regularly as recommended.

However, if you’re uncomfortable performing the battery replacement yourself or if you need to replace the entire key fob unit, the costs can be higher:

Dealership Key Fob Replacement

Replacement OEM key fob: $100 – $300
Programming/coding cost: $50 – $100
Total dealership key fob replacement cost: $150 – $400

The exact cost of a key fob replacement can vary depending on your Lexus model, the type of key fob, and whether any additional programming or coding is required.

FAQs About Changing Lexus Key Fob Batteries

Do I need to reprogram the key fob after changing the battery?

In most cases, no reprogramming is necessary after a simple battery change. However, if you’re replacing the entire key fob unit or if the key fob isn’t communicating with your Lexus after the battery replacement, reprogramming may be required. Consult your owner’s manual or a Lexus dealership for specific instructions.

Is it difficult to change the battery myself, or should I take it to a dealer?

Changing the key fob battery yourself is generally a straightforward process that requires minimal tools and effort. However, if you’re uncomfortable working with small electronics or if your key fob has a more complex design, it may be easier and safer to have a Lexus dealer handle the replacement.

How often should I expect to change the key fob battery?

Most key fob batteries will need to be replaced every 1-2 years, depending on usage. However, this can vary based on factors like the battery type, the age of the key fob, and how frequently you use the remote functions.

Can I use any CR2032 battery, or does it have to be from Lexus?

While any CR2032 lithium coin cell battery should theoretically work, it’s always recommended to use a genuine Lexus OEM battery or one specifically designed for automotive key fobs. These batteries are typically of higher quality and may offer better performance and longevity compared to generic batteries.

Is there a way to check my key fob’s battery level?

Unfortunately, most Lexus key fobs do not have a built-in battery level indicator. However, some Lexus models may display a warning message on the dashboard or emit an audible alert when the key fob battery is running low.

Changing the battery in your Lexus key fob is a simple and inexpensive task that can save you from the hassle and potential security risks associated with a non-functioning key fob. By following the step-by-step guide provided in this article, you can easily replace the battery yourself and ensure that your key fob continues to work seamlessly, providing you with the convenience and security features you’ve come to expect from your Lexus.

However, if you encounter any difficulties or uncertainties during the process, don’t hesitate to seek professional assistance from a Lexus dealership or a reputable automotive locksmith. They have the necessary expertise and resources to diagnose and resolve any issues with your key fob, ensuring that it’s functioning correctly and keeping your vehicle secure.

Regular maintenance and timely battery replacements are essential for prolonging the lifespan of your Lexus key fob. By being proactive and addressing any potential issues early on, you can avoid the inconvenience and potential risks associated with a malfunctioning key fob, ensuring that you can continue to enjoy the full range of features and benefits that your Lexus has to offer.

Let’s Finish

changing the battery in your Lexus key fob is a straightforward task that can save you money and hassle in the long run. With the right tools, a little bit of patience, and the guidance provided in this article, you can confidently tackle this maintenance task and keep your Lexus running smoothly for years to come.