Program New Keys after ECM flash (1 Viewer)

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I apologize if this has been covered, but I could not find the steps to take after the ECM immobilzer has been reflashed. I purchased a 99 LC100 with only a valet key. I ordered in 2 new keys with the buttons and have had them cut to fit ignition. I sent off the ECM to have the immobilizer flashed and will receive it soon. I would like to have instructions to program the keys to start and to program the keys to use the buttons on the master keys I purchased. Thanks for the input.
 
What I found in FAQ was how to program if you have an existing master key. In my case I am starting from scratch.
 
What I found in FAQ was how to program if you have an existing master key. In my case I am starting from scratch.

Contact the folks who are reflashing your ECU for instructions. My guess is that the ECU will arrive in 'program' mode and would accept any 'chipped' key as a 'Master'. After that...you can program the remainders.

The best thing would have been to have sent your cut keys along with the ECU and let them program them in for you. Hopefully your keys are a 4C chip (and functional) and you have the correct length key (there is a short and long model).
 
I'm sure you have already solved this but for the future reference of others the locksmith on eBay that flashed mine supplied directions. The directions were a little incorrect but it ended up working. Essentially directions state: after ecu install 1. Insert first master (do not turn key), the security light should go from blinking to solid when the key is inserted then turn off when the key is registered. Remove key.
2. Repeat for subsequent keys making sure the valet key is the last key because whatever key is programmed last the ecu automatically makes the valet.
3. Press the brake pedal.

Now when I did mine, a 98 lc. The security light flashed then went solid when the first key was inserted, but stayed solid. I left it in for about 20 min but I never saw the light go out. I decided to risk it and go to the second key. The light stayed on when I removed the key and for a second went out when I put the second key in. I went to the last key (the valet) and the light did turn off when the key was inserted. Keys worked when tested after.
I had my ecu flashed by kings security in California through eBay for 90$ after 10% off eBay coupon. I paid for outgoing shipping about 14$ priority from Virginia. Took a little over a week full circle. They got it on a Friday at 2pm and sent it back out on Monday I think, priority mail. I ordered two fob keys on Amazon for 45$ and the dealer cut them by the vin for free. The valet key was original oem as far as I know.
 
@Mauser is the King on this topic.
 
 

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