I have seen this posting is a few places, does it work:
Is the key cut? I am not sure if it's the same for the MDX but here is the instruction for programming the 2nd generation TL key
1...your new key
2...a MASTER KEY (one with the remote in it)already programmed to car
to program the transponder- (thats the immobilizer part)
sitting in dr. seat, put the master key in ignition
, and turn to on.engine OFF. press the gas pedal 5 times to floor and release. now press brake 6 times (press and release)
remove master key from ignition. install new key and turn to on...engine off. press gas to floor once. now wait. the security light
will blink for about 45-60 seconds, then it will go off if you did it correctly. once the light is off, car should start.
For the remote part. in drivers seat WITH DOOR OPEN. start with door unlocked. first put master key in ignition, turn to on, then back off and remove. using the lock/unlock button on drivers door. press lock.. then unlock 5 times.(lock,unlock,lock,unlock,lock,unlock,lock,un lock,lock,unlock)
Close drivers door, open drivers door.
Performe lock/unlock procedure again.
insert key in to ignition and turn to on, then back off and remove.(at this point the doors should lock and unlock by themselves ONCE)
Now press both lock and unlock buttons on REMOTE. release after about 1.5seconds. now press just the lock button on remote.
now open and close the drivers door a couple
times to close programming. if you did it right, remote will now work.