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What to do after replacing a Lexus battery?

After replacing the battery in your Lexus, there are a few important steps you should take to ensure your vehicle is running smoothly and safely. This article will guide you through the necessary post-battery replacement procedures to get your Lexus back on the road.

Resetting the Battery Sensor

One of the first things you'll need to do after replacing the battery is to reset the battery sensor. This sensor monitors the battery's charge and helps the vehicle's electrical system function properly. To reset the battery sensor, follow these steps:

Turn off the ignition and remove the key from the vehicle.

Locate the battery sensor, usually near the battery itself.

Disconnect the negative (-) cable from the battery terminal.

Wait for at least 30 seconds, then reconnect the negative cable.

Start the engine and let it run for a few minutes to allow the sensor to reset.

After completing these steps, the battery sensor should be reset and your Lexus should be ready for the next steps.

Resetting the Engine Control Unit (ECU)

The Engine Control Unit (ECU) is the computer that manages your Lexus's engine and other systems. When you replace the battery, the ECU may need to be reset to ensure it's properly calibrated. To reset the ECU, follow these steps:

Turn off the ignition and remove the key from the vehicle.

Locate the ECU, which is usually under the dashboard or in the engine bay.

Disconnect the negative (-) cable from the battery terminal and wait for at least 30 seconds.

Reconnect the negative cable and start the engine.

Allow the engine to run for a few minutes to allow the ECU to reset.

Once the ECU has reset, your Lexus should be ready for normal operation.

Resetting the Clock and Other Settings

After replacing the battery, you may need to reset the clock and other settings in your Lexus. This can typically be done through the vehicle's infotainment system or by consulting your owner's manual. Some common settings that may need to be reset include:

Clock

Radio presets

Seat and mirror positions

Personalized settings

Be sure to check all of your Lexus's settings and make any necessary adjustments to ensure everything is functioning as expected.

Conclusion

Replacing the battery in your Lexus is an important maintenance task, but it's not the end of the process. By following the steps outlined in this article, you can ensure your Lexus is running smoothly and all of its systems are properly reset after the battery replacement. If you have any further questions or concerns, be sure to consult your owner's manual or contact a Lexus service professional for assistance.

Do I need to do anything after changing my car battery?

Do I need to reset anything after changing my battery? Yes. You may need to reset the clock, radio, power windows, and key fob. Some cars also require a battery management system reset to ensure proper charging.

Can you change a Lexus battery yourself?

Yes, you can replace a Lexus battery yourself, and many people find it a straightforward process. You will need basic tools like a 10mm wrench or socket, safety gear like gloves and glasses, a new battery, and optionally a memory saver device. The process involves disconnecting the terminals in the correct order (negative first), removing the hold-down bracket, swapping the battery, and then reconnecting everything in reverse order (positive first).

You can watch this video to learn how to replace the battery in a Lexus RX350: 57sViktor G AutomotiveYouTube · Sep 25, 2023
Before you begin

Gather your tools: You'll need a new battery, a 10mm wrench or socket, gloves, safety glasses, and an optional memory saver device or booster cables. A terminal brush and anti-corrosion spray are also helpful.
Park and secure the vehicle: Park the car on a level surface, turn it off, and engage the emergency brake.
Locate the battery: Open the hood and find the battery, which may be under an engine cover you need to remove by popping out some clips with a flat blade screwdriver.

Disconnect and remove the old battery

Remove the negative terminal first: Use a 10mm wrench to loosen the nut on the negative (black) terminal and carefully remove the cable. Tape the end of the cable to prevent it from accidentally touching the battery.
Remove the positive terminal: Now, remove the positive (red) terminal cable in the same way.
Remove the hold-down bracket: Loosen the nut on the bracket that holds the battery in place and remove the bracket to free the battery.
Lift out the old battery: The old battery can be heavy, so use the handle if one is available. Lift it straight out of the tray.

This video shows how to disconnect and remove the old battery: 1mredonKiLausYouTube · May 5, 2017
Install the new battery

Clean the terminals: Use a battery terminal brush to clean both terminals and the cable connectors before installing the new battery.
Place the new battery: Gently lower the new battery into the tray, making sure it is oriented correctly with the positive and negative terminals in the right positions.
Secure the new battery: Reinstall the hold-down bracket and tighten it securely, but be careful not to overtighten and crack the battery casing.
Connect the positive terminal first: Attach the positive (red) cable and tighten the nut securely.
Connect the negative terminal last: Attach the negative (black) cable and tighten it, completing the circuit.
Apply anti-corrosion spray: Spray the terminals to prevent future corrosion.
Reinstall covers: Put any engine or battery covers back on, ensuring all clips and covers are properly re-engaged.

Final steps and troubleshooting

Start the car: Start the engine. The first time it may stall or run roughly, which is normal. If it stalls, just restart it.
Reset systems: You may need to reset some settings after the battery has been disconnected. This can include manually closing and opening the sunroof and turning the steering wheel fully left and right after starting the car to re-initialize the steering angle sensor.

Do I need to reset anything after replacing the battery?

Yes, you will likely need to reset several things after replacing a car battery, as disconnecting it can erase settings for the clock, radio presets, and power windows. For modern vehicles, you may also need to reset the engine control unit (ECU) or even "register" the new battery to ensure the charging system functions correctly, which sometimes requires a scan tool.
Immediate steps and settings

Start the car: Let the engine run for at least 10-15 minutes to allow the alternator to charge the new battery and the car's computer to adjust to the new power source. The idle may be rough initially as the computer recalibrates.
Reset electronics: Manually reset the clock, radio presets, and seat memory settings.
Check automatic windows: The one-touch or auto function for power windows may stop working and need to be reset. Consult your owner's manual for the specific procedure, which often involves holding the window switch up or down for a few seconds after it reaches its limit.

Advanced resets for modern cars

ECU recalibration: The engine control unit (ECU) often has an "adaptive memory" that needs to relearn driving habits. Driving the car will allow the emissions and fuel systems to recalibrate automatically over time.
Battery registration/programming: On many newer cars, especially those with a Battery Management System (BMS), the computer needs to be told that a new battery has been installed. This is often done with a scan tool and is important for the charging system to work efficiently and not overcharge the new battery. If the new battery is a different type (e.g., from a standard to an AGM), programming is especially important.
Key fob/alarm system: If your key fob stops working, you may need to resync it. Try inserting the key into the ignition and turning it to the "on" position without starting the engine.

If problems persist

Hard reset: If there are lingering electrical issues, a "hard reset" can be performed by disconnecting the battery again and touching the two disconnected cables together for 15-30 minutes to fully drain the system's capacitors.
Seek professional help: If warning lights or other issues continue after driving for a while, the problem may require a professional diagnosis with an OBD-II scan tool, especially if a battery registration is needed.

How to reset Lexus after battery change?

To reset a Lexus after a battery replacement, first reconnect all cables and then drive the car to allow the systems to recalibrate. You may also need to reset specific functions like the windows and infotainment system using manual procedures. For persistent issues or a hard reset, disconnect the battery terminals for 30 minutes to fully discharge the system.
After reconnecting the battery

Start the engine: and let it idle for 2–3 minutes without touching the gas pedal to allow the idle relearn procedure to begin.
Drive the vehicle: for about 10 miles to let the systems fully reinitialize.

This video demonstrates how to reset the idle relearn procedure after a battery change: 36sHelping U onlineYouTube · Sep 22, 2020
Reset specific features

Windows: Roll each window all the way down, wait a few seconds, and then roll it all the way up and hold it for a few seconds.
Key fob and alarm: If the fob doesn't work, try inserting the key into the driver's door lock and manually locking/unlocking it. You may need to press the unlock button on the fob.
Infotainment system: For a soft reset, try turning the ignition to "ON" (without starting) and holding the power/volume button for 10–15 seconds, or try the "Settings" > "Info and security" > "System reset" procedure on large displays.

This video shows how to reset the windows after a battery change: 58sKarrs KarsYouTube · Mar 25, 2021
Hard reset (if needed)

Disconnect the negative and positive battery terminals.
Touch the two disconnected terminals together for 15–30 minutes to discharge residual power.
Reconnect the terminals (positive first, then negative) and start the engine.

This video demonstrates how to hard reset the car battery: 1mUpFix Automotive Electronics RepairYouTube · Jan 3, 2023
If problems persist

Check all fuses, especially those related to the infotainment system.
Look for loose wiring connections, particularly around the display or stereo unit.
If the battery warning light remains on, seek professional diagnosis.

Kevin Bennett

Company Owner

Kevin Bennet is the founder and owner of Kevin's Autos, a leading automotive service provider in Australia. With a deep commitment to customer satisfaction and years of industry expertise, Kevin uses his blog to answer the most common questions posed by his customers. From maintenance tips to troubleshooting advice, Kevin's articles are designed to empower drivers with the knowledge they need to keep their vehicles running smoothly and safely.