I have a 2000 LS400, with an original factory three-button remote transponder (new battery) that presently STARTS the car but will no longer open/close the doors (or arm/disarm the alarm).

I have tried the method described below, with subtle variations. What's frustrating is that in an hour of trying and re-trying the procedure, I actually got it up to STEP 8 three times (but in a different set of instructions it didn't mention holding LOCK and UNLOCK buttons simultaneously). I'm confident if I can get it back in program mode, I can finish the programming procedure.

However, now, no matter how quickly or slowly I follow these instructions, I CANNOT get into programming mode anymore! It's like there's some magic extra step required once I've failed to program the key.

What's interesting is that 99% of my attempts FAIL when it comes time to step 7: I can LOCK using the electric lock switch, but pressing UNLOCK doesn't actually unlock.

In the three times where I have gotten up to step 8, pressing LOCK/UNLOCK on the electric switch DOES work. So it seems as if there's something subtle about steps 1-6, or somehow the system has locked out this particular key for 3 failed attempts.

Any expert insights?

Steve

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1. Sit in the driver's seat and lock all the doors.

2. Unlock and open the driver's door.

3. Insert the key into the ignition and remove it (don't turn it...just
remove it).

4. Using the MANUAL lock switch on the driver's door, lock and unlock
the door 5 times.

5. Close the door.

6. Open the door.

7. Lock and unlock the driver's door 5 times but this time use the ELECTRIC lock. Insert the key into the ignition and turn
it to the "ON" position. Remove the key. The locks will now cycle by themselves.

If the door locks do not cycle (lock and unlock) by themselves then the car isn’t in programming mode and you must start over.

8. On the remote, press and hold the LOCK and the UNLOCK button at the same time for no more than 2 seconds.

9. On the remote, press the LOCK button for no more than 1 second.

10. Close and open the door to end the programming procedure.

 

trying disconnecting the battery an tie both terminals together for about 5 minutes... this should drain all the power in the vehicles system (make sure u have the radio code before u do this if needed) upon power up all settings SHOULD be reset allowing u to access program mode again...

 

An update: using the ELECTRIC lock switch instead of the Manual lock, I was able to get a bit closer. I am now able to occasionally enter programming mode, though there still seems to be some magic related to (perhaps) waiting a minimum number of seconds after a failed attempt before one can try again.

However, my attempt to reprogram the key for keyless entry mode has not worked. There are multiple methods, some indicate holding BOTH lock and unlock to begin the reprogram, others suggest only lock.

Does anyone know the definitive sequence for a 2000 LS400?

 

Im having the same problem..I have a 99 Ls400 and I got the key to turn the car on but i cant findout how to program the remote to unlock and close the doors.

 

Here are the key programming instructions for the 98-00 LS, GS and SC.

 

See thats the thing thats the procedure I have and its not workin.ill get from a-e then the reat doesn't work.