wotcham8

My 03 RX300 FWD came with 1 valet key and 1 flat key (with transponder removed from key card - so it unlocks the doors, but does not start the car). I've looked at different options and the best solution so far has been offered by a local locksmith:

Reflash the ECU, cut and program 2 new master keys, re-program existing valet key and, hopefully, cut new flat key with new transponder in key card (haven't confirmed the flat key solution yet).
$400 without remotes ($700 with remotes).

At these prices, I am most likely going to do without the remotes although as I'm spending $400 on this fix, I may treat myself to aftermarket flip keys as I'm not a fan of carrying sharp objects in my pocket. Before I bite the bulllet, does anyone have a better/more cost-effective solution?

salimshah

Have you checked with Lexus dealership? Make sure you give them the vin number.

Salim

JAB

I'm not an expert, but my understanding is that you don't 'reprogram' either a new master key, or the existing valet key, but you 'reprogram' the ECU to recognize the chips in those keys. Anyone got a better understanding?

hypervish

Once the ECU is re-flashed, you can then program a new master key. Well that's my understanding anyways...lol

salimshah

Technically you are correct. The key is just a dumb sending unit (magnetic flux and the transmitted signals do not change). The smarts are built in the ecu to recognize and compare.

Salim

wotcham8

Good news: If all you want is a spare key that unlocks your doors and starts your car:-

You don't need Lexus to install a new ECU ($1500)
You don't need a locksmith to reflash your existing ECU ($400)
You can just clone your valet key.

Lowest price I've seen is $60. Ace Hardware did it for me for $150 (the price of living in paradise).

So, just to be clear, this does not give you a master key. But it is the best solution for me as it gives me a spare key so I don't have to worry about losing my one remaining valet key.

salimshah

I still suggest pricing it out by the dealer. What you would have paid the dealer would have been key cutting cost blank key cost (some dealers accept blank keys from the customers). You could have save some money in paradise.

Salim

wotcham8

Salim, I did go to the dealer. The dealer's solution was to replace the ECU for $1500 and then to program 2 Master keys for an additional $700.

It was only by doing my own research that I discovered the ECU could be re-flashed and 2 Master keys programmed for $400.

Further research revealed that the simplest solution was to sidestep the ECU altogether and simply clone the valet key.

I'm sharing this online because dealers will not offer this simple, relatively inexpensive, fix.

salimshah

The dealer solution was the Cadillac solution.

If you had asked for duplicate wallet key, the price would have been less.

The other cheap alternative with option to upgrade would be to buy a smart key off ebay or amazon and have it cut to match the personalization (groove) by a locksmith or dealer (if they agree). If and when you change the ecu with a master key, you could register the key.

I am glad you did visit the dealership as at some point Lexus has modified the ECU and master key is not needed to register new key.


Salim

wotcham8

That's right. This issue affects RX first generation (up to 2003) only. Your RX is 2nd generation. For first generation RXs, the only solution the dealer will offer is to replace the ECU. Locksmiths will generally offer to reflash the ECU. You have to find a locksmith with a cloning machine that is capable of cloning the valet key. The machines are expensive and not all locksmiths have them. ACE Hardware is the only locksmith on Maui that could do this.

MovieStar

I was somewhat more fortunate then wotcham8, The closest one to me was 200+ miles from me. Last year he virginized my ecu for 150.00, this year when it lost it's memory he said that he would do it at no charge. I personally like having the master key with fob. When it's hot outside I can open the windows without having to run outside to do it LOL

bufferdan

Pop immobilizer chip out of flat emergency key. Glue it to ignition behind panel. Get a aftermarket keyless entry and a couple blank keys cut. This is how mine has been for many years. You get a better keyless entry and remote start if you want, dont have to worry about crap keys breaking and it costs less than $100 if you diy.