2005 GX470 - Tried Flat Key and Now Car Won't Start

[IslanderGX470]

Hello,

I am a new member and this is my first post on this forum.   Hopefully I am posting in the correct place.  🙂  I decided to test my flat key after eighteen years and followed the owners manual instructions on how to use it with the transponder chip.  It did not work, so I tried multiple times.  I then tried the valet key and it didn't work.  My next and last step was to use my master key which was working fine.  That did not work.  I tried all three keys multiple times again.  It just clicks and the dashboard lights up as shown in the pic.  I can roll the windows up/down, lock the doors but it won't start.  Did I accidentally activate the engine immobilizer by using the transponder chip in the flat key case?  Any ideas what I can do?   

 

 

[RX400h]

There could be several reasons why your Lexus GX470 is not starting with the flat key and transponder chip:

1. Wrong Key: You might be attempting to use a key for a different vehicle¹.
2. Locked Steering Wheel: If the steering wheel is locked, you can unlock it by turning the steering wheel from left to right while simultaneously turning the ignition key on¹. If this doesn’t work, it’s recommended to have the vehicle towed to a Lexus dealership as the key may be worn/damaged or there may be a problem with the ignition switch itself¹.
3. Battery Issue: If you recently changed or disconnected the battery, your Lexus may not start because it has lost synchronization between the key and the vehicle². You can try pressing the Start button with the keyfob².
4. Key Battery: The battery in your key might need to be replaced³.
5. Error Code: If an error code is preventing the vehicle from starting, you can try clearing the code with a code reader or by disconnecting the negative terminal for 5 minutes⁴.

If none of these solutions work, it’s best to consult with a professional mechanic or your local Lexus dealership for further assistance.

[IslanderGX470]

15 hours ago, RX400h said:

There could be several reasons why your Lexus GX470 is not starting with the flat key and transponder chip:

1. Wrong Key: You might be attempting to use a key for a different vehicle¹.
2. Locked Steering Wheel: If the steering wheel is locked, you can unlock it by turning the steering wheel from left to right while simultaneously turning the ignition key on¹. If this doesn’t work, it’s recommended to have the vehicle towed to a Lexus dealership as the key may be worn/damaged or there may be a problem with the ignition switch itself¹.
3. Battery Issue: If you recently changed or disconnected the battery, your Lexus may not start because it has lost synchronization between the key and the vehicle². You can try pressing the Start button with the keyfob².
4. Key Battery: The battery in your key might need to be replaced³.
5. Error Code: If an error code is preventing the vehicle from starting, you can try clearing the code with a code reader or by disconnecting the negative terminal for 5 minutes⁴.

If none of these solutions work, it’s best to consult with a professional mechanic or your local Lexus dealership for further assistance.

Thank you Dave for your response.  I went through these steps:

1) The key is the correct key.  I tried all three keys - master, valet and flat key with chip transponder in the case

2) I tried this and it still just clicks when I try to start it.

3) I just had major repairs done the day prior, but everything worked fine until I tried the flat key with chip transponder.  

4) The battery was recently replaced and it worked fine until I tested out the flat key to see if it would work. 

5) I disconnected the negative terminal for 15 minutes, reconnected and it still just clicks when I try to start.  

I believe this may be related to the flat key/chip transponder.  The moment I tried it and it did not work is when all keys stopped working.  

It sounds like my next step is to have it towed to my Lexus tech where I had the repairs done and get this figured out.    Thanks again for your advice and guidance.   

[RX400h]

I'm sorry none of those tips worked, Doug. It is perplexing to say the least.