How to Program Your Lexus IS300 Key Fob: A Step-by-Step DIY Guide

As a Lexus IS300 owner, dealing with key fob issues can be a common yet frustrating experience. Whether you’ve lost a key, bought a replacement, or simply want to avoid expensive locksmith fees, programming your Is300 Key Fob yourself is entirely achievable. Many owners face the dilemma of a broken or lost key fob and are often quoted hefty prices for programming at dealerships or locksmiths. Fortunately, there’s a way to program both your key and remote functions right in your driveway, saving you time and money. This guide, tailored for IS300 enthusiasts, provides straightforward instructions to program your key fob and remote, ensuring you’re back on the road without breaking the bank.

Key Programming for Your Lexus IS300 (Master Key)

This section will guide you through programming a new master key for your Lexus IS300. It’s crucial to use a master key for this procedure, not a valet key, to ensure successful programming. Follow these steps carefully:

1. Insert Existing Master Key: Begin by inserting a previously programmed master key into the ignition. It’s important not to turn the ignition on at this stage. Simply insert the key into the slot.

2. Pump the Gas Pedal: Locate your gas pedal and press it fully, then release it, repeating this action a total of five times. Ensure you are pressing and releasing fully each time.

3. Engage the Brake Pedal: Next, find your brake pedal and press and release it six times. Similar to the gas pedal, make sure each press is a full press and release.

4. Remove the Master Key: Take out the initially inserted master key from the ignition.

5. Insert the New Key: Now, insert the new, unprogrammed key that you wish to program into the ignition. Again, do not turn the ignition on.

6. Press the Gas Pedal Once: Press and release the gas pedal just one time.

7. Wait and Watch the Security Light: This is a critical step. After pressing the gas pedal, wait for one minute. During this minute, observe your security light on the dashboard. It should start blinking. Continue waiting until the security light stops blinking. Once the blinking ceases, your new key is successfully programmed. To finalize the process, press the brake pedal one time.

Understanding the Security Light: The security light is your visual guide throughout this programming process.

• Step 1: When you insert the programmed master key, the security light should initially turn off.
• Steps 2-5: The security light will remain off during these steps.
• Step 6: After you press the gas pedal with the new key inserted, the security light should begin to blink. This indicates the system is in programming mode.
• If the Security Light Comes On After Step 4: If you see the security light illuminate after removing the master key in step 4, it indicates a potential issue or timing problem. If this happens, immediately stop the procedure and start again from step 1.

Troubleshooting Key Programming:

• Speed is Key: If your car doesn’t enter programming mode, it might be due to performing the steps too slowly. Try to execute the gas and brake pedal presses more quickly.
• Master Key Verification: Ensure you are indeed using a master key and not a valet key. Valet keys typically cannot be used for programming.
• Restart if Unsuccessful: If you fail to program the key on your first attempt, don’t worry. Simply restart the entire procedure from step 1 and try again, focusing on speed and accuracy of each step.

Remote Programming for Your Lexus IS300 Key Fob

After successfully programming your key to start the ignition, you’ll want to program the remote functions (lock, unlock, panic) as well. Follow these steps to program your IS300 remote:

1. Prepare the Vehicle: Begin by ensuring all doors of your Lexus IS300 are closed and locked. Then, unlock and open only the driver’s side door. Leave the driver’s door open throughout the initial steps.

2. Insert and Remove Key (No Ignition): Take the key you want to program the remote for and insert it into the ignition cylinder. Immediately remove it – do not turn the ignition on.

3. Lock and Unlock Cycle (5 Times): Locate the electric lock switch on your driver’s side door panel. Use this switch to perform a lock and unlock cycle five times. The sequence should be: Lock, Unlock, Lock, Unlock, Lock, Unlock, Lock, Unlock, Lock, Unlock. Perform these actions using the electric switch, not manually.

4. Close and Open Driver’s Door: Physically close the driver’s side door, and then open it again.

5. Lock and Unlock Cycle Again (5 Times): Using the electric lock switch once more, repeat the lock and unlock cycle five times, just as you did in step 3.

6. Ignition Sequence: Insert the key into the ignition cylinder. Turn the key to the “ON” position (without starting the engine), then immediately turn it back to the “OFF” position, and remove the key from the ignition.

7. Observe Door Lock Cycle: At this point, if you’ve successfully entered programming mode, you should observe the door locks cycling automatically. They should lock and then unlock by themselves. This is your confirmation that the car is ready to learn the remote signal.

   Troubleshooting Remote Programming Entry: If the door locks do not cycle automatically in step 7, it means the car has not entered programming mode. In this case, you will need to start the remote programming procedure over from step 1. Double-check that you are performing each step correctly and at a reasonable pace.

8. Initiate Remote Signal (Lock & Unlock Buttons): Take the remote you are programming. Simultaneously press and hold down both the Lock and Unlock buttons on the remote for no more than 2 seconds.

9. Send Lock Signal: After releasing the Lock and Unlock buttons, immediately press and release the Lock button on the remote for no more than 1 second.

   Confirmation of Remote Programming: After performing steps 8 and 9, listen and watch for the door locks to cycle again.

   • One Lock Cycle (Success): If the door locks cycle one time (lock then unlock), it indicates that the car has successfully accepted the remote’s programming signal.
   • Two Lock Cycles (Failure): If the door locks cycle two times, it means the programming attempt has failed.

   Improving Remote Signal Reception: The most common reason for remote programming failure is a weak or missed signal from the remote to the car. To improve signal reception, consider these tips:

   1. Stand Outside the Car: When performing steps 8 and 9, try standing outside of the car, closer to the vehicle’s receiver.
   2. Button Press Duration: Avoid holding the remote buttons down for too long. Stick to the recommended durations of “no more than 2 seconds” and “no more than 1 second”.

   If the car remains in programming mode (you have a short window to program remotes), you can repeat steps 8 and 9 to try programming the remote again. If you wait too long and the car exits programming mode, you’ll need to restart the entire remote programming process from step 1.

10. End Programming: To finalize the remote programming procedure, simply close and then open the driver’s door. This action signals to the car that you have finished programming remotes, and it will exit programming mode.

Congratulations! You have now successfully programmed your Lexus IS300 key fob and remote. Enjoy the convenience and savings of DIY key fob programming! If these instructions worked for you, consider sharing your success to help other IS300 owners in the community.