How to reset Lexus key fob after battery replacement?

If you've recently replaced the battery in your Lexus key fob, you'll need to reset it to ensure it continues to work properly with your vehicle. This process is relatively straightforward and can be completed in just a few steps.

Steps to Reset Lexus Key Fob After Battery Replacement

1. Locate the reset button: On the back of your Lexus key fob, you should see a small reset button. This is typically located near the battery compartment.


2. Press and hold the reset button: Using a small, pointed object like a paperclip, press and hold the reset button for approximately 5-10 seconds.


3. Release the reset button: Once the reset button has been pressed for the recommended duration, release it.


4. Test the key fob: Try locking and unlocking your Lexus vehicle using the key fob. If it works as expected, the reset process is complete.

If the key fob still doesn't work after following these steps, you may need to contact your local Lexus dealer for further assistance.

Why Reset the Lexus Key Fob After Battery Replacement?

Resetting the key fob after replacing the battery is important for a few reasons:

• Synchronization: The key fob needs to be synchronized with your Lexus vehicle's security system to function properly. Resetting the key fob helps establish this connection.


• Troubleshooting: If the key fob isn't working correctly after a battery replacement, resetting it can help resolve any issues and restore full functionality.


• Preventative maintenance: Regularly resetting the key fob, even if the battery hasn't been replaced, can help maintain its reliability and longevity.

By following these simple steps, you can ensure your Lexus key fob continues to work seamlessly with your vehicle after a battery replacement.

How do I resync my Lexus key fob?

To reprogram a Lexus key fob, you can use a DIY method for older models, which often involves a specific sequence of door lock and ignition key movements, or you may need to use a programming tool and/or a visit to a locksmith or dealership for newer models. Check your specific car's model and year to find the correct procedure, as the process varies significantly.
 
You can watch this video to learn how to program a Lexus key fob for push-to-start vehicles: 57smyFirstech AcademyYouTube · Jul 28, 2015
For older models (typically 1998-2005)
This method requires a key and access to the driver's side door. 

• Open the driver's door, but make sure all other doors are closed. 
• Insert the key into the ignition and remove it. 
• Within 40 seconds, lock and unlock the driver's door five times (about one second per operation). 
• Close and then open the driver's door. 
• Lock and unlock the driver's door five more times. 
• Insert the key into the ignition. 
• Turn the key to the "on" position once to add keys, twice to erase existing keys, or three times to check the number of keys. 
• Remove the key, and the doors will lock and unlock one to three times to confirm the mode you selected. 
• Within 40 seconds, press and release the lock and unlock buttons on the key you want to program. 
• Within three seconds, press any button on the fob to confirm. The doors will lock and unlock once to confirm success. 
• If you need to program additional keys, repeat the last steps within 40 seconds of programming the last one. 

For newer models (and some older ones)

• Use a programming tool: Many newer vehicles require a programming tool to be connected to the car's OBD2 port. A working key and the new key will be needed to use this method. 
• See a locksmith: A professional locksmith can often program new keys, and this may be more affordable than going to the dealership. 
• Consult a dealer: If you cannot program the key yourself, a Lexus dealership can handle this for you. This may also be necessary if your car is a 2023 model or newer, as some have restrictions that prevent DIY programming. 
• For push-to-start keys: Programming a key that requires a push-to-start button typically requires a tool, a working key, and a specific procedure. The process is often similar to the one described for older models but with the push-to-start button instead of a key ignition. 

Tips

• Timing is crucial: Pay close attention to the timing requirements, as the process is sensitive to the timing of each step. 
• Check your model: Before you begin, research your specific Lexus model and year to ensure you use the correct procedure. 
• Use a replacement fob: You can also buy a replacement fob and transfer the internal components from the old fob, which can save you from needing to reprogram the new fob. 

Do you need to reprogram a key fob after changing the battery?

No, you do not need to reprogram a key fob after changing the battery, as the programming is stored in the vehicle's memory and isn't erased when the fob battery is replaced. However, some older or very specific models might require a simple resync procedure, and if the fob still doesn't work, the issue is likely not the battery itself. 
This video explains how to resync a key fob after changing the battery: 37sJMG ENTERPRISES YouTube · Nov 6, 2022
What to do

• Just replace the battery. In most modern cars, you can simply swap the old battery for a new one and it will work immediately. 
• Resync if necessary. If the fob doesn't work after changing the battery, the car may need to be resynced. The procedure varies by car, but it often involves a simple sequence of actions, like turning the ignition on and pressing a button on the fob multiple times. 
• Troubleshoot if it still doesn't work. If the fob still doesn't work after the resync, the battery was likely not the original problem. The issue could be a loose connection, a faulty fob, or a problem with the car's receiver. 

How to resync (example)

• For many cars: Insert the key, turn it to the "on" position, and press the lock button on the fob several times (e.g., 4 to 12 times) within 30 seconds. Turn the ignition off and test the fob.
• Consult your car's manual. Check your vehicle's owner's manual for the specific procedure, as it can vary by make and model. 

How do I reset my Lexus after replacing the battery?

To reset your Lexus after a battery change, start by performing a hard reset by disconnecting both terminals, touching them together for at least 30 minutes, and then reconnecting the positive cable first. Next, reset specific systems by turning the ignition to the "ON" position, letting the engine idle for a few minutes, and performing individual component resets like those for the power windows, steering angle sensor, and power hatch. Finally, drive the vehicle for about 10 miles to allow the computer to relearn and adjust to the new battery. 
Hard reset (Recommended first step)

• Disconnect the negative terminal, followed by the positive terminal. 
• Touch the disconnected positive and negative cables together for at least 30 minutes to drain residual power and reset all vehicle modules. 
• Reconnect the positive battery cable, followed by the negative cable. 

This video demonstrates how to perform a hard reset on a car battery: 1mUpFix Automotive Electronics RepairYouTube · Jan 3, 2023
System and component resets

• Idle relearn: Turn the ignition to "ON" (do not start) for 30 seconds. Then, start the engine and let it idle for 2-3 minutes without touching the gas pedal. Turn off the car and repeat this process. 
• Window reset: For each window, roll it all the way down, wait a few seconds, then roll it all the way up and hold the switch for a couple of seconds. Repeat for each window. 
• Steering angle sensor: If the steering wheel light stays on, turn the steering wheel slowly all the way to the left and then all the way to the right until the light goes off. 
• Rear hatch: If your vehicle has an automatic rear hatch, you may need to manually open and close it a few times. 

This video shows how to reset the electric windows on a Lexus after a battery change: 58sDaringBeefcakeYouTube · Dec 5, 2021
Drive the vehicle 

• After performing the resets, drive the vehicle for about 10 miles to allow the computer to recalibrate and learn the new battery's performance. 
• Be aware that the engine may run roughly for a few minutes as the idle learning system adjusts. 

Why is my key fob not working after replacing the battery?

If your key fob still doesn't work after replacing the battery, first check that the new battery is oriented correctly and that the battery contacts are clean and making good contact. If that doesn't solve the problem, you may need to reprogram the key fob, check for internal damage like a broken circuit board or buttons, or, in some cases, the issue could be with the car itself.
 
Basic troubleshooting steps
This video demonstrates how to check and clean the battery contacts in a key fob: 1mBStride DIYYouTube · Oct 28, 2023

• Check battery orientation: Make sure the new battery is installed with the correct positive (+) and negative (-) sides facing the right way. 
• Clean contacts: Use a cotton swab with isopropyl alcohol to clean the battery contacts and the circuit board for any grime or corrosion. 
• Adjust battery prongs: Gently bend the small metal prongs inside the fob upwards to ensure they are making firm contact with the battery. 
• Check for a protective sticker: If the new battery came with a protective warning sticker, make sure it was removed before installing, as it can block the connection. 

Reprogramming and advanced fixes
You can watch this video to learn how to reprogram your key fob: 37sJMG ENTERPRISES YouTube · Nov 6, 2022

• Reprogram the fob: The fob may have lost its programming with the car. Consult your car's owner's manual for the specific reprogramming procedure, or look it up online for your vehicle's make and model. 
• Reset the car's system: Sometimes, disconnecting your car's 12V battery for a few minutes can reset the system and resolve the issue. Be sure to check your manual for any special procedures for disconnecting the battery. 

When to seek professional help

• Internal damage: The circuit board or buttons may be damaged from a drop or water exposure. A professional can check for damage or re-solder loose connections. 
• Faulty component: The fob itself might be defective and need replacement. A parts store can test the fob to see if it's working correctly. 
• Vehicle issue: If the fob works with a spare but not your main one, the problem may be with your car's receiver or locks, not the fob itself.