This is how to program your 1998 Toyota Sienna replacement remote keyless entry fob alarm by yourself at home without going to the dealer.

Ensure key removed from ignition switch.
Locate central locking signal control module Fig. 1 [1].
With harness multi-plug still connected, jump harness multi-plug terminals 1 and 9:
System should now lock and unlock vehicle once.
Press any remote transmitter button:
System should now lock and unlock vehicle once to confirm.
Repeat button procedure to program second remote transmitter.
To exit programming mode: Remove jump lead from central locking signal control module harness multi-plug.
Refit all components in reverse order of removal.
NOTE: A maximum of 2 remote transmitters can be programmed.
NOTE: Programming remote transmitter erases all previous codes. Both remote transmitters must be programmed at the
same time.
Fig. 1 Fig. 2
1998 toyota sienna xle programming

For more information about these remotes, or to place an order, please click on the link below:
https://www.carandtruckremotes.com/toyota-remotes-sienna-remotes.html