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2003 Lexus RX300 Key Fob Remote Programming Instructions

Posted by Keyless Entry Remote on Jun 19th 2013

Here are the programming instructions for a 2003 Lexus RX300 Key Fob Remote. If you need an extra Key Fob or Replacement Fob for any vehicle you might have visit us at You can also leave comments or suggestions at the bottom of this blog and if you like what we provide please forward on to your friends & family; people like you are our best advertising tool!


NOTE: The remote keyless entry system is equipped with 2
transmitters, having 2 unique vehicle access codes programmed
into the wireless door lock ECU.


There are 4 registration modes:

Add Mode
Adds a transmitter (remote) without erasing existing transmitter
codes. Four transmitter codes can be registered at one time. If number
of registered codes exceeds 4, previously registered codes are erased
in order, starting with first registered code.

Rewrite Mode
Erases all previousLy registered transmitter codes and
reprogram new transmitters.

Confirmation Mode
Informs user of number of existing transmitter codes already
programmed in system.

Prohibition Mode
Erases all existing registered transmitter codes and cancels
wireless door lock operation. Use this function if transmitter is lost
or stolen.


1) To begin programming, remove key from ignition switch.
Ensure driver's door is open and unlocked, and all other doors are
closed. Insert key into ignition switch, and then remove it.

2) Complete the following in 40 seconds or less: press door
lock switch (the one that controls all the locks) to LOCK position,
and then within one second, press door
lock switch to UNLOCK position. Repeat procedure continuously until
door locks have been locked and unlocked 5 times. Close, and then open
driver's door.

3) Complete the following in 40 seconds or less: repeat
procedure in step 2), except for closing and opening driver's door.

Insert key into ignition switch. To enter desired mode, turn ignition
switch to ON position and back to LOCK position (one cycle), within
one second, the specified number of times. See REGISTRATION MODE
SELECTION table below. Remove key from ignition switch. Registration
of confirmation code is complete after door locks cycle. Be sure to
continue as below.

Mode - - - No. Of Ignition Switch Cycles
Add = 1
Rewrite = 2
Confirmation = 3
Prohibition = 5

4) If any mode, other than confirmation mode is selected, go
to next step. If confirmation mode was selected, door locks will cycle
0-4 times depending on how many transmitter codes are stored in ECU.
Example: two stored codes equals 2 door lock/unlock cycles.

5) Complete the following in 40 seconds or less: if add mode,
rewrite mode or prohibition mode is selected, to confirm proper
initiation, door locks will automatically cycle one time for add mode
(at the end of step 3),
2 times for rewritemode and 5 times for prohibition mode. Press
transmitter LOCK and UNLOCK buttons simultaneously for at least 1.5
seconds, and then within 3 seconds, press any transmitter button for
at least one second.

6) If within 3 seconds, door locks cycle one time, new
transmitter code has been successfully accepted. Go to next step. If
door locks cycle 2 times, new transmitter code was not accepted. To
program an additional transmitter or to make a second attempt, return
to step 5) within 40 seconds.

7) Registration of recognition codes is complete under any of
the following conditions:

* Forty seconds has elapsed since wireless door lock ECU has
* Driver's door is closed.
* Key is inserted into ignition key cylinder.
* Four recognition codes are registered at one time.

Having trouble programming the remote or just want a professional to program the remote for you?  Enter your city or zip code in the search box below to find a professional key fob installer in your area.


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