Passenger door unlocks but won’t lock
01-19-20, 05:14 PM
#1
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Passenger door unlocks but won’t lock
I’m having a strange issue with my 97 SC400. The passenger door will not lock with the power locks but will unlock. The only to lock it is by manually doing so from the interior or using the key on the passenger door. When I try to lock it using the keys or the switch I can see it trying to lock but retracting back to the unlock position. Any clue as to what is causing this and how to fix it?
01-20-20, 12:35 AM
#2
It is possible that the passenger side door lock actuator is beginning to go out. Best to test it to be sure but if the solenoid/mechanism only wants to work for one of the two actions that could be the problem. They are a pain to get in there and replace without removing the window glass temporarily but it can be done with a lot of painter's tape (to hold the window in place with the regulator fully removed, a lot of patience, a few tools and a screw extractor kit (and replacement OEM screws that hold in the lock actuator to the door frame). There is a DIY writeup on the forum that shows how to do it.
First thing is to be sure that actuator is actually beginning to fail for certain. It's an annoying but doable job to get an old assembly out and a new one in due to the VERY tight fit inside the door with the window still installed so it's best to be totally sure if that needs to be done or not. It should be easier if the window glass is temporarily removed for this job since that's what causes the extremely tight clearance issue to remove and replace an old door lock actuator assembly in the first place.
Now there is also a door lock ECU (there is a separate ECU for many things on these cars) that communicates with the door lock actuators but usually it's the actuators themselves present issues once these cars get a LOT of years on them. I had to replace my driver's side module once and later my passenger module side once.
The last thing I can think of is to check inside the door with the trim/card off and the noting which of the metal cables goes where in the door switch. You want to use a flashlight and look inside at the mechanical parts of the door to see if anything is amiss or if the little plastic connector/insulator that goes onto the top arm coming from your passenger side door lock actuator is in good shape and NOT cracked or in danger of disintegrating.
That tends to be a separate issue (and easily solved with a $1.00 replacement part from Lexus if it's caught before it's a problem) where that little plastic armature insulator breaks apart due to age/stress and lets the door lock mechanism's metal arm slide out of position and get crushed/bent the next time the window goes down. In that unfortunate situation you'd just need a new door lock actuator altogether. It's not a common thing really but it's been documented here before and we know to look out for it or just replace those little plastic clip/insulators with new ones as a precaution to future-proof against the potential issue.
You'd want new little insulators with a new door lock actuator install anyway IF your car needs that done.
First thing is to be sure that actuator is actually beginning to fail for certain. It's an annoying but doable job to get an old assembly out and a new one in due to the VERY tight fit inside the door with the window still installed so it's best to be totally sure if that needs to be done or not. It should be easier if the window glass is temporarily removed for this job since that's what causes the extremely tight clearance issue to remove and replace an old door lock actuator assembly in the first place.
Now there is also a door lock ECU (there is a separate ECU for many things on these cars) that communicates with the door lock actuators but usually it's the actuators themselves present issues once these cars get a LOT of years on them. I had to replace my driver's side module once and later my passenger module side once.
The last thing I can think of is to check inside the door with the trim/card off and the noting which of the metal cables goes where in the door switch. You want to use a flashlight and look inside at the mechanical parts of the door to see if anything is amiss or if the little plastic connector/insulator that goes onto the top arm coming from your passenger side door lock actuator is in good shape and NOT cracked or in danger of disintegrating.
That tends to be a separate issue (and easily solved with a $1.00 replacement part from Lexus if it's caught before it's a problem) where that little plastic armature insulator breaks apart due to age/stress and lets the door lock mechanism's metal arm slide out of position and get crushed/bent the next time the window goes down. In that unfortunate situation you'd just need a new door lock actuator altogether. It's not a common thing really but it's been documented here before and we know to look out for it or just replace those little plastic clip/insulators with new ones as a precaution to future-proof against the potential issue.
You'd want new little insulators with a new door lock actuator install anyway IF your car needs that done.
Last edited by KahnBB6; 01-20-20 at 12:46 AM.
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Barbary (02-12-23)
01-24-23, 03:15 PM
#3
Did you ever get this issue fixed? I'm having a problem where my power door switches (both sides) will unlock, but not lock. I've tested the switches and they are both okay. Next is to try swapping the door lock ecu. Hopefully that does it.
01-24-23, 04:59 PM
#4
Are you experiencing this in only hot weather by chance? In the summers my doors don't like to lock using the power lock functions and if I can recall correctly, this is a known common issue from hot temperatures affecting the solenoids.
01-24-23, 05:33 PM
#5
No, its happening now in the winter. There are several things I need to check. One is also the wire that goes between the door in that rubber boot. Sometimes those get pinched or broken over time.
02-10-23, 07:44 AM
#6
Okay, bump to this thread because I'm not having any luck.
Car is a 1993 SC300. The door lock switches on both doors will UNLOCK the doors, but neither switch will LOCK the doors. I have tried swapping known working switches into each side, but the same thing happens - switches will unlock, but neither will lock the door.
I've been trying to get a part number for the "door lock ECU" to see if I can find a replacement, but no luck. I've also checked the fuses and none were out.
Does anyone have any suggestions on what could be the cause? It seems that if a wire was broken or something, the switches wouldn't work at all (since they are on a connected circuit.) Could this be an actuator issue? It just seems strange that it would be on both sides at the same time.
Car is a 1993 SC300. The door lock switches on both doors will UNLOCK the doors, but neither switch will LOCK the doors. I have tried swapping known working switches into each side, but the same thing happens - switches will unlock, but neither will lock the door.
I've been trying to get a part number for the "door lock ECU" to see if I can find a replacement, but no luck. I've also checked the fuses and none were out.
Does anyone have any suggestions on what could be the cause? It seems that if a wire was broken or something, the switches wouldn't work at all (since they are on a connected circuit.) Could this be an actuator issue? It just seems strange that it would be on both sides at the same time.
02-15-23, 08:53 PM
#7
Sounds like a door lock ecu issue, or some input to the ecu that prevents the doors from locking. I just can't recall what things might prevent locking, so not sure what to suggest there. I can look in all of my stuff I can send you an ecu if you send me a pic of what it looks like. I don't remember which one of the units is the door lock ecu.
Another thing to consider is the ground wire in the drivers door. That is common to lose that ground, all kinds of weird stuff happens like windows don't work, speakers don't work, etc. And it will affect both sides because the controller is in the drivers door. Probably not your issue, but does happen.
Another thing to consider is the ground wire in the drivers door. That is common to lose that ground, all kinds of weird stuff happens like windows don't work, speakers don't work, etc. And it will affect both sides because the controller is in the drivers door. Probably not your issue, but does happen.
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