Can't Get Keyless Entry To Go Into Program Mode

[DMW 99 RX300]

I've followed the instructions to a T but can't get the system to verify (system locks and unlocks doors 1,2 or 5 times depending on the mode) that it is in programming mode. I'm trying to get it into Confirmation mode.

Here are the instructions that I'm following up to the point where the system should verify that it is in programming mode:

MODES OF REGISTRATION

There are 4 registration (programming) modes:

Add Mode - Adds a transmitter 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.

REGISTRATION OF RECOGNITION CODE

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. Go to

next step.

2) Complete the following in 40 seconds or less: press door

lock switch 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. Go to next step.

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. Remove key from ignition switch. Go

to next step.

REGISTRATION MODE SELECTION

Registration 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

1-4 times depending on how many transmitter codes are stored in ECU.

Example: two stored codes equals 2 door lock/unlock cycles.

Registration of confirmation code is complete after door locks cycle.

Any ideas of what I could be doing wrong?

[mikey00]

What is the source of thes directions? Are you sure they are the right ones for a RX300? Sorry, I don't have time to check right now but they do look different then I am used to seeing.

[DMW 99 RX300]

They are from the 99 RX300 service manual:

http://www.red928.com/Lexus/Lexus_-_RX-300...Manual_1999.pdf

[mikey00]

They are from the 99 RX300 service manual:

http://www.red928.com/Lexus/Lexus_-_RX-300...Manual_1999.pdf

I do remember reading that there is a mistake in the service manual key programming. Do a search here and over at the other lexus site. Or try comparing with directions here:

http://www.toy-lex.com/

[DMW 99 RX300]

There must be a problem with the system because it will not go into programming mode; and I'm a programmer! The only difference in the instructions at toy-lex.com was that the first step said to lock all doors and then unlock the driver's door. The rest of the procedure was exactly the same. It just won't go into any programming mode. I had no problem programming the keys; I just can't program the remote so I'm stuck with only one working remote until I can get enough information to troubleshoot the problem.

Since it is not even getting into programming mode, I don't have to consider transmitter/receiver issues. That leaves the control unit and the inputs: door switch (which works because the foot light turns on/off), lock/unlock switch (works), and the Ignition switch (works). So the problem is likely the control unit or an input connection to the control unit.

If I can determine the pinouts and signals for the inputs, I should be able to simulate locking/unlocking and door opening/closing by using jumper wires at the control unit. I want to put it in Confirmation Mode (Ignition on/off 3 times) which the system should respond with one to four lock/unlock cycles to indicate the number of remotes programmed.

[mikey00]

I was sure I remembered reading at some time about a error in the 99 manual regarding remote programming. However, I just did a pretty extensive search and came up empty handed. So I will have to blame this on my memory. I do know that many have used the toy-lex instructions and they work and as long as they are the same as the manual, the manual must be correct.

The only other long shot I can think of here is: I wonder if any one has done a door lock actuator repair on your RX and in doing so has disabled an input necessary for remote programming.

http://us.lexusownersclub.com/forums/index...showtopic=41219

[DMW 99 RX300]

This is the best RX300 Remote Programming guide and is the same procedure for 1999 thru 2003:

These images are posted permanently on my server so this post can be pinned.

[DMW 99 RX300]

Interesting idea. I assume that the only way to determine whether or not the mod has been done to any of the doors is to take apart each door enough to see inside. For now, I'll just live with one remote since I'm the only one driving the car.

[mikey00]

I know you said you had no problem programming the keys (just the remotes) but I just need to clarify. The key is just a dumb piece of cut metal with a plastic head that is cut to turn the ignition cylinder. All the smarts are in the remote electronics. So when you first program the key to start the car the remote electronics must be in it and it is the remote electronics that is actually getting programmed to allow the car to start. This must be completed and the key must be able to start the car before moving on to program the remotes. If it is not done then you can't enter program mode when you try to program the remotes.

Next you move to the remote programming steps. You use the key that you just programmed to start the car with the electronics in place for all the steps in this process.

I am not trying to say you are doing anything wrong but this is where others have had problems with the programming process.

[MMatheny]

After trying about half a dozen "procedures" to get my remote entry programmed, I finally found the instructions on this site to actually work!

http://www.toy-lex.com/programming.html

[Trompii]

Did you ever get this to work?

[rOcKeRo83]

Alright guys, I had the exact same issues with my 2000 RX 300 and I understand it's 2021 but I hope this helps anyone who comes across this forum with the same issues.  After I programmed the key, the fob programming never activated.  I realized it was because my lock actuators were bad and if they don't physically lock and unlock it won't trigger the programming sequence.  I replaced all 4 door actuator motors, not the unit but the motors that drive the locks inside the units.  I read a lot of people's fob stopped working after replacing the units.  Maybe they need to be OEM and need to reprogram the fobs.  I really don't know, that's why I only replaced the motors from eBay, originals, not knock offs.  MABUCHI FC280PC-22125 its the item number.  After the tedious task of disassembling the door panels and removing the actuators from the lock mechanism.  I split them open, replaced the motors.  Reinstall everything back together.  Tested the locks and windows because you will need to loosen the window rails, because they get in the way of removing the units.  And like it happened to me for not testing the windows, they only want half way down.  I had to redo the two front door panels in order to adjust the rails.  Anyways, I started the sequence and this time it did activate, and I was able to complete my fob programming without a hitch.  If anyone needs a more detailed explanation on how to do it.  I'll gladly type up step by step how I completed my project.  Am hope this helps someone else out there.  

P.S.  Am pretty sure this applies to all Lexus that require the same procedure.

Att: JV

 

[timmerk]

21 hours ago, rOcKeRo83 said:

Alright guys, I had the exact same issues with my 2000 RX 300 and I understand it's 2021 but I hope this helps anyone who comes across this forum with the same issues.  After I programmed the key, the fob programming never activated.  I realized it was because my lock actuators were bad and if they don't physically lock and unlock it won't trigger the programming sequence.  I replaced all 4 door actuator motors, not the unit but the motors that drive the locks inside the units.  I read a lot of people's fob stopped working after replacing the units.  Maybe they need to be OEM and need to reprogram the fobs.  I really don't know, that's why I only replaced the motors from eBay, originals, not knock offs.  MABUCHI FC280PC-22125 its the item number.  After the tedious task of disassembling the door panels and removing the actuators from the lock mechanism.  I split them open, replaced the motors.  Reinstall everything back together.  Tested the locks and windows because you will need to loosen the window rails, because they get in the way of removing the units.  And like it happened to me for not testing the windows, they only want half way down.  I had to redo the two front door panels in order to adjust the rails.  Anyways, I started the sequence and this time it did activate, and I was able to complete my fob programming without a hitch.  If anyone needs a more detailed explanation on how to do it.  I'll gladly type up step by step how I completed my project.  Am hope this helps someone else out there.  

P.S.  Am pretty sure this applies to all Lexus that require the same procedure.

Att: JV

 

Thank you! I actually had this same exact issue today after replacing my Body ECU. I need to re-pair the key fob but the driver side lock actuator fails after two lock/unlock sequence, so I can't get into the fob programming mode. Would you mind sending the step-by-step procedure? I'm having a hard time getting the units out, but I do know how to get the door panels off. Also, do you have an ebay seller you recommend for a legit MABUCHI motor? I am worried about knock-offs. Thanks again!

Edit: also, all 4 door actuators are bad in mine. A local mobile locksmith who knows about this problem says I only need to worry about fixing the driver side actuator. Know if that's true? 

[Bykfixer]

It seems pretty common that the driver door actuator is the only bad one in many cases where none work. 

My 04 GS 300 has one at the driver door and one on the passenger side rear. I just leave the car unlocked and don't leave anything visible a thief would want unless they're some kinda weirdo who wants to steal my drinking cup or window shade. 

I do leave the valet option engaged so the trunk cannot be opened without a key. But it's a car not a hatchback SUV. Don't know if that one has a valet option that prevents the rear hatch from opening without a key. 

[timmerk]

On 7/15/2021 at 9:09 PM, timmerk said:

Thank you! I actually had this same exact issue today after replacing my Body ECU. I need to re-pair the key fob but the driver side lock actuator fails after two lock/unlock sequence, so I can't get into the fob programming mode. Would you mind sending the step-by-step procedure? I'm having a hard time getting the units out, but I do know how to get the door panels off. Also, do you have an ebay seller you recommend for a legit MABUCHI motor? I am worried about knock-offs. Thanks again!

Edit: also, all 4 door actuators are bad in mine. A local mobile locksmith who knows about this problem says I only need to worry about fixing the driver side actuator. Know if that's true? 

Update that might help someone if they replaced their Body ECU module: I desoldered the EEPROM chip from the original bad module and replaced the EEPROM in the replacement module with it since I figured the EEPROM was the only place in the module that could be storing the fob pairing data. It worked! I used a $50 hot air rework station off Amazon to desolder it, and then a very fine soldering iron tip to solder it back. This is my poor soldering job, but it works!