I purchased my RX300 with only one master key and one valet key. My master key broke at the base where the plastic meets the metal, and in the process of obtaining an aftermarket key replacement I lost the immobilizer chip. I have the new aftermarket key housing with the metal key portion and the transponder in it without the immobilizer chip. My question is can I reprogram a new master key with the valet key using that method of inserting the valet key, stepping on the accelerator 5 times, stepping on the brake pedal 6 times, inserting new immobilizer chip key? Or am I f*#&ed and have to spend the money at the dealership?

 

For first gen, you need a Master key to program other keys.

You can try to live with the valet key

Or purchase a new ECU with master key. Use the transponder with your current key blade [make copies of it]. Install the ECU.

Next option would be buy the ECU and master key and change out all key cylinders to the new key.

Check with the dealer and see if they can give you a discount, else do your shopping from a reputable salvage yard. LKQ comes to mind.

Salim