booboofoo

Hi team!

I have created this thread for the benefit of users who have the 1992-1996 years of ES300 - but there's also information here which will help everyone who has a 92-96 ES300.

After doing loads of research Ive uncovered some interesting bits of knowledge which (I think) are worth sharing for future readers using the Search function.

The first two years (1992-1993) used a Wireless Key Receiver which had a matching ROM chip inserted into the Receiver.

They keys were matched to the Receiver via chips built into the transmitter keys..

For a while (but no longer) if you broke one of your wireless transmitter keys you could buy a NEW matching pair of (two) transmitter keys with an added ROM chip to insert in your existing Receiver.

Think of the process as kinda sorta like changing a SIM Card in your phone.

It was a crude replacement system, but it worked.

Please Note: that option hasn't been available for sale for at least a decade. And it was expensive too - like $600 USD for two new keys and a new ROM chip.

Now, here's where it gets interesting.

Even though the years 92-96 of the ES300 all used "one button entry keys", during the years 1994-1996 Lexus used a universal "one button" transmitter key which was used in SC400's, GS300's, and ES300's.

As a result, you can still buy those keys as a blank master. The official part No is 89742-24070 and they currently sell for roughly $105 USD as at Dec 2023.



It turns out the 1994-1996 Wireless Receiver can be retrofitted into the 92-93 cars.

However, there's a catch. You still need to use Wireless Transmitter Keys which match the correct FCC ID frequency.

Sadly, a 1992-1993 wireless ES300 key has an incompatible FCC ID for the 1994-1996 ES300 Wireless Door Control Receiver to work.

The FCC ID for a 94-96 Wireless Transmitter Key is HYQWDT-B and the key I showed in the photo above matches that frequency.

The FCC ID for a 94-96 Wireless Door Control Receiver is HYQWDR-C and the part No is 89741-33110 and there are still plenty for sale on eBay.

Hence it is possible to buy up to four blank Master Keys and have them cut to your original 92-93 door locks, but then program them for the later 94-96 Wireless Door Control Receiver







I hope this thread helps someone some day!

LILEVO

iTrader: (1)

If everyone has the same 94-96 key FCC and receiver, wouldn't everyone's key open any 94-96 ES wirelessly?

How does it make the signal unique to each vehicle?

booboofoo

My understanding is you can use any key 94-96 from any of the above mentioned cars and link it to the 94-96 Receiver - assuming you have access to the car and assuming you go through the linking process. I recall reading a thread - I think I still have a link to it - in which a user did precisely that. He used keys which wouldn't fit the locks but they would still act as transmitters.

So yes, it appears all the 94-96 replacement keys have a unique transponder ID like the earlier 92-93 keys, but they use a different frequency range.

Arsenii

It seems like the question is about what makes a specific fob unique to a specific car.

The idea is that FCC ID is not the actual key, it's just a standard number assigned by Federal Communications Commission (FCC) for each device that occupies a specific Wireless Band, which dictates what Frequency Band the specific device is allowed to occupy without causing interference, aka havoc, among other devices that are currently out there. I mean, it wouldn't be fun if your fob would suddenly gain an ability to unlock your car and launch a missile at the same time.

What makes each fob unique is the Key Code stored in it. Each time you press a button, the Key sends a signal, containing a specific key, followed by a command assigned to a button. Newer cars utilize what's called a Rolling Code system, which forms a unique key after each entrance, making it a lot harder to get a code for your key by simply listening to the same frequency as your Fob.

Below is a more detailed video on the subject.


Hope this helps and best of luck!

LILEVO

iTrader: (1)

Ok, that makes sense. So it's basically like a garage door opener. It's not a fixed signal or frequency.

LILEVO

iTrader: (1)

I checked and the 92-93 keys and rom chip are still available through Lexus. The part number for 2x keys and chip is: 89705-50051-RK. Can be had for about $450-$475.