Hi everyone,

New to the forums, and first post. Looking for help diagnosing a problem with the central locking system on my 2003 Rx300:

Only the driver’s door unlocks/locks with the remote. I’ve tried pressing the button twice/several times. Reading some of the posts here, it seems door lock actuators are a common problem, but I find it unlikely that all three passenger door actuators are faulty. Or could that be possible? I have checked the fuses that sound like they have to do with locks, but all are fine. Does anyone know if there is specific fuse that is linked to the central locking? Car has a new battery, and I have also replaced the key fob battery.

When using the lock button inside the car, I do hear a thunk from the doors, but they do not lock/unlock. Only the rear hatch door does.

Any ideas of what the issue could be ?

Thanks!
Henrik

 

Welcome to the 300 club!

your door motor/acculator is out.
Get a used door Acculator from EBAY ( much cheaper than Lexus) and pull the door apart.
It is not hard but will take some time for access and you can go to YouTube to see how to pull door start. My 01RX300 with 98,000 had 2 doors go out but they were changed
and going strong after all theses years

 

Thanks for the quick response! So it's common for all three actuators to fail at the same time? That was what I found so unusual.

Henrik

 

Yep not common but car is over a quarter century old now.

99% sure your door acculators are out

 

True. Thanks for your help!

 

If the door locks fail to operate properly, bu the electronic switch on the driver and front passenger door, then the actuator is the issue. [exception can be the wiring to the actuator too]. Typically the motors go weak [make sound but can not push the lock over] and then finally quit working.

Caution: Never be in a hurry to put back the door panel if you have worked on the lock mechanism. If the door is closed shut with the panel on, you will have to destroy the panel to open the door.

Salim

 

Thank you, Salim. I was just surprised that it would happen to all three passenger doors. I've seen the thread on the DIY on changing actuators, so may attempt that. Although I am not mechanically inclined. And thanks for the heads up on putting the panel back.

Best,
Henrik

 

If you hear/feel the same clunk on each of the three doors when using the drivers door lock buttons or the remote button then, yes, all three actuators are weak. If you don't hear anything when operating the switch/remote, then your problem may lie elsewhere.
New actuators are horrendously expensive, as is their installation labor cost at the dealer (or even an independent). Go to a car stereo specialty store and ask if they can slave a generic actuator alongside the factory setup.

 

That's good info, thank you. What does it mean to "slave a generic actuator" though? Thanks!

 

The question is do you want to replace the motor or the actuator. The actuator is a bigger assembly. Earlier if you wanted an actuator you had to go to Lexus/Toyota parts. If you go for repairs at Lexus they will replace the whole actuator.

For the longest time the only option was to add an electromechanical device to pull on the wire/rod to the lock. [either the thumb operated lock-**** or the key operated rod (only for the front doors).

If you are DIYer you can remove the actuator and replace the motor.

Historically the motor replacement technique was posted in GS400 forum and then in RX firstGen we have been posting the repair technique. I did replace my motor.
Then some members found out that motor was spinning backwards. So make sure you get the right motor.
Eventually Actuators (aftermarket) became available. I have no experience with them.

Salim

 

Thanks, Salim. I know pretty close to zero about how lock mechanisms work - I assume it's all three motors that would need to be replaced then? And doing that by removing all three actuators. Overall, being mechanically untalented myself, I think this procedure sounds above my paygrade... especially since it would be for three separate doors. And it sounds like the cost to have a professional do it is high. Might have to learn to just live with it.

 

My driver's front and rear passenger locks don't function any longer. Thankfully in this car I can easily reach any of the locks and manually operate them. The door panels are super simple to take off, but the rest of the process is beyond my patience level. It would be a great challenge though, maybe when it warms up!

 

Given the age of the vehicle, replacing 2 or more with OEM dealer provided actuators would be cost prohibitive.

removing the actuator and worse putting it back [relatively it requires more skill to put it back] and not following caution will make the situation worse.
Surgery of the actuator, needs more mechanical dexterity [there is cutting involved].

From 1920s to 1990s people had a door key, so the remote is just a convenience thing. From the inside, yes push of a button vs reaching all doors one by one is a minor irritant. So do your number crunching and make your decision.

Caution ... Salim getting on a soap box:
Potential cost of repair starts getting higher as the vehicle ages. At times you have to walk away instead of repairing. If owner does not have DIY skills they should not own 20yr vehicle specially if it is luxury [what ever luxury means to you ... to me it would be not the run of the mill] brand. I would suggest, plan to replace.

Salim

 

My thoughts exactly, Salim. If it's the actuators, I will just live with it. My original query was if it could be something else. Thanks all for great input!

 

Yup. That's why you either chose to live with it, do the (tedious) motor replacement, or see if you can find a car stereo store to install a generic slave actuator. Given the oddball design of the OEM RX300 mechanisms, I don't know if the latter is an option but a decent installer might know.