Doors Won't Lock When Car Interior Gets Hot....

[stjr]

I'm the original owner of an '01 IS300. The following is something that just started happening last summer. When I try to lock the car after driving the car for an hour or more during a sunny, hot day, the car doors will not lock (using the remote). The lights do not flash and there is no "beep" telling me the car is locked.

I did some observations and noticed the following:

1. When using the remote to lock the doors, the actual interior door lock buttons appear to "stick" and are not being moved completely to the "locked" position by the door lock actuators. This situation happens mostly on the left front (driver's) door and left rear door (both at the same time).

2. If I lock the doors manually (when the door lock buttons "Stick") using the door's interior lock buttons, then hit the lock button on the remote, the lights flash and the "beep" is heard indicating the car is locked.

3. There appears to be no problem unlocking the car with the remote.

4. This problem always occurs when the car is in the sun and the interior gets hot.

5. If it is REALLY hot out (I live in Arizona) and I have the A/C on, the car's doors lock just fine using the remote.

I am hoping someone might have encountered this before and has an easy fix (short of "going to the dealer").

Steve

Mesa, AZ

[IanH]

Well an interesting problem, not heard of this before.

So what can I say to help you?

When you say it 'sticks' can you feel abnormal resistance to locking by hand or by the key ?

IE is this mechanical?

Well i doubt it but have to ask..

So what happens when electrical stuff gets hot !!

Resistance increases, current flow goes down, bad connections get worse.

So first thing is to check you battery voltage, everything off and car sitting for a while, say 30 -60 minutes. Digital Multimeter, 20V range, note temperature of battery in case we need it later.

Waiting for your reply.

[stjr]

Hello Ian!

Thank you so much for the quick response!

When I lock the doors manually using the interior "buttons", they turn like I'm moving them through "a thick grease". They do turn; but with some effort (again, only when the interior is hot).

I need a little direction for measuring the temperature of the car battery; are you talking "under hood" temperature or the actual temperature of the battery itself? If you're talking the temperature of the battery itself; I'm thinking you mean service temp?? Please let me know.

I will check the battery voltage across the terminals (AZ heat is known for "chewing up and spitting out" batteries. Typical battery life is 3 years; + / - 6 months). My current battery is about 2 years old. But the problem occured even the battery was new.

Steve

Well an interesting problem, not heard of this before.

So what can I say to help you?

When you say it 'sticks' can you feel abnormal resistance to locking by hand or by the key ?

IE is this mechanical?

Well i doubt it but have to ask..

So what happens when electrical stuff gets hot !!

Resistance increases, current flow goes down, bad connections get worse.

So first thing is to check you battery voltage, everything off and car sitting for a while, say 30 -60 minutes. Digital Multimeter, 20V range, note temperature of battery in case we need it later.

Waiting for your reply.

[IanH]

Hello Ian!

Thank you so much for the quick response!

When I lock the doors manually using the interior "buttons", they turn like I'm moving them through "a thick grease". They do turn; but with some effort (again, only when the interior is hot).

I need a little direction for measuring the temperature of the car battery; are you talking "under hood" temperature or the actual temperature of the battery itself? If you're talking the temperature of the battery itself; I'm thinking you mean service temp?? Please let me know.

I will check the battery voltage across the terminals (AZ heat is known for "chewing up and spitting out" batteries. Typical battery life is 3 years; + / - 6 months). My current battery is about 2 years old. But the problem occurred even the battery was new.

Steve

Well an interesting problem, not heard of this before.

So what can I say to help you?

When you say it 'sticks' can you feel abnormal resistance to locking by hand or by the key ?

IE is this mechanical?

Well i doubt it but have to ask..

So what happens when electrical stuff gets hot !!

Resistance increases, current flow goes down, bad connections get worse.

So first thing is to check you battery voltage, everything off and car sitting for a while, say 30 -60 minutes. Digital Multimeter, 20V range, note temperature of battery in case we need it later.

Waiting for your reply.

I am only interested in the battery temp, if the car has been off for some time then the ambient approx temp will do.

This is so i can check the voltage at this temp if we need too. However based on your reply it doesn't sound like its an electrical/battery/wiring issue at all !!

So you are saying the other locks don't feel like this, moving in thick grease ?

and at lower temperature they not only work but don't feel like this ?

Well it sounds like something is binding in the solenoid/ lock assembly.

I would expect something like this with cold not heat.

I suggest taking the door panel off the rear door, since you can still drive around for a few days, when its hot enough to produce the symptoms.

lubricate the lock mechanism, and check the solenoid action. maybe disconnect the linkage and check each piece. I think it will be obvious when you find it, the solenoid give a hard shove so whatever this is will appear seized to hand movement.

[IanH]

i will hand lock mine to see what they feel like ....

[stjr]

Hi Ian;

Thanks...and you're right. NOW is the time of year I need to get this issue resolved; while the weather is mild (not 112 in the shade). And I believe I saw an entry some where in this forum that gave good instructions coincerning the removal of the door panels.

The car turns 9 February 2nd. And it's always been an "Arizona car". So I'm thinking the heat and (lack of) humidity is starting to take it's toll. Oh....I just turned 49,000 miles on it!!

Again...Thank You so much for your help! It was great talking with you.

Steve

i will hand lock mine to see what they feel like ....

[IanH]

Well mine are very easy to hand lock using the inside knob.

So maybe the handle assembly is worn out or jamming.

mine has 138K btw, but this may be more years and door uses than miles.

I Expect if you disconnected the handle assembly and try and actuate using the rod it will be very difficult.

Its hard to imagine its the solenoid is bad, but check any intermediate rods and pivots. I don't know what it looks like in there, but will look at the FSM when i get a chance.

Just a side note, i had the first year legacy and the handle assembly would go bad, several were replaced under warranty.

Out of warranty I couldn't adjust or fix. very strange. But buy a new handle assembly and rod, don't adjust or touch, drop in, worked great for some more years.

and the newer replacements did last longer.

[stjr]

Great suggestions Ian. And thanks for checking the manual operation of the door locks on your car. I will follow your suggestions and check everything out. I am considering documenting the whole process with pictures. We'll see how ambitious I get!

Thanks again!

Steve

Well mine are very easy to hand lock using the inside knob.

So maybe the handle assembly is worn out or jamming.

mine has 138K btw, but this may be more years and door uses than miles.

I Expect if you disconnected the handle assembly and try and actuate using the rod it will be very difficult.

Its hard to imagine its the solenoid is bad, but check any intermediate rods and pivots. I don't know what it looks like in there, but will look at the FSM when i get a chance.

Just a side note, i had the first year legacy and the handle assembly would go bad, several were replaced under warranty.

Out of warranty I couldn't adjust or fix. very strange. But buy a new handle assembly and rod, don't adjust or touch, drop in, worked great for some more years.

and the newer replacements did last longer.

[dan01&06]

Did you ever solve the problem of the door locks not working when the car is hot? I have an '01 LS430 and have experienced the same problem the last two summers. It is also an Arizona car. I'm beginning to think a computer box is getting hot, but that is a wild guess. Could you let me know?

[AZ-LS430]

Same here, 01 LS430 in the Arizona summer heat having similar door lock issues. Locks work fine in the winter. Anyone find resolution?

[kayanite]

On 7/10/2016 at 1:01 AM, AZ-LS430 said:

Same here, 01 LS430 in the Arizona summer heat having similar door lock issues. Locks work fine in the winter. Anyone find resolution?

Realize this is a bit of a necro, even with his latest bump, but am curious as well.  Today was the first day I didn't really drive any where during the day, but went out to the car and noticed this happening.  Tonight I went up to the store while it was cooler out and absolutely no problems at all.  Spam clicked the inside and the fob and no problems.  While earlier in the day I was lucky to get it to unlock more than the drivers side door.

[GoodMonday]

SC430 -- 2004 in San Diego.  It's hot today, and this specific problem is back.  The remote (has a new Sony batterty) unlocks, but won't lock both doors.  The key does lock the doors.  I'm sure that after sundown everything will work well again.

[DesertDoug]

Same here, 01 LS430 in the Palm Springs area summer heat having similar door lock issues. Locks work fine when it's cooler. Anyone find resolution?

[Hoffy5]

Ok Same here on my sc430, The dealer has replace both Door Actuators are know to fail!  Well,  after doing that, my SC Remote will not lock the doors with remote.  Can  lock and unlock manually with Key!  

Has anybody had any Modules replaced or similar problem that finally got fixed??  Appears to be a wireless receiving problem??

Thanks!!

[ISFATTY]

Anyone resolve the issue? I am about to replace/rebuild the lock actuators but wanted to see if there was solution to this issue. I have an ls430 locks will not work in the heat but when ac cools down the car from the inside after a long drive they function normally