Programming a 05 Tundra Remote
 

This one comes from member nhparrott:

To add an additional remote on the DC factory system

1. Insert key into ignition key cylinder, then pull it out. (Assume from step 3 that driver door is open)
Perform steps 2 & 3 Within 40 sec.
2. Press door lock control switch (for manual operation) 5 times to LOCK/UNLOCK at approx. 1 sec. interval.
3. Close and open driver side door
Perform steps 4 , 5, 6 & 7 Within 40 sec.
4. Press door lock control switch again (for manual operation) 5 times to LOCK/UNLOCK at approx. 1 sec. interval.
5. Insert key into ignition key cylinder.
6. Turn ignition switch from LOCK to ON and back to LOCK at approximately
1 second intervals, 1 time (This sets ADD Mode)
7. Remove key from ignition key cylinder.
Within 3 sec, Body ECU automatically performs power door LOCK-UNLOCK operation to inform which mode has been selected. (1 LOCK-UNLOCK)
Perform steps 8 & 9 Within 40 sec.
8. Press LOCK and UNLOCK switches on transmitter simultaneously within 1.5 sec.
within 3 secs of step 8 perform step 9
9. Press either switch for more than 1.5 sec.
Within 3 sec,Body ECU automatically performs power door LOCK-UNLOCK operation to show whether registration has been completed correctly or not.

LOCK-UNLOCK Occurs Once - Registration of recognition code has been completed.

LOCK-UNLOCK Occurs Twice - Registration of recognition code has failed.