2000 Rx 300 Rear Door Sensor?

[nightmoon]

It all started with a trip to Home depot for my husband to buy a door skin, aka 3/8" luan. It was 5' x 7' and I was wondering how the heck he thought I'd get this in my RX300. I got it in up to the back of the front seats and it was hanging out the back a foot and a half or so and I couldn't close the back hatch/door all the way.

So... I got a short bungee cord from my toolbox and hooked one end through the bottom door latch ("U shaped bolt looking thing" on the back floor. This is what the door lock connects to.) and the only upper place I could get it to go was in the door lock itself. This meant 'moving with my hand only, the door locking mechanism so it 'closed' and i could get a hole to put the end of the bungee cord through.

I thought everything was fine. I got home ok, took the bungee cord off, put the luan in the shop, then I had problems.

I tried to close the back door and it jut hit on the latch but didn't close or lock. OOPS! So i opened the door and figured out the lock was still 'closed'. So I pulled up on the handle and the lock 'opened'. I successfully closed the rear hatch and thought I was fine.

Until I hit the 'door lock' on the key. I just got the alarm that means a door isn't closed tightly and none of the car doors locked. I manually locked the rear hatch. That worked ok. I hit the 'lock' switch inside the drivers door and that locked all the locks ok (even the rear one). And I can still unlock the car with the remote key.

However, there is the 'door open' signal on the dashboard and it won't go off. And I still cannot lock the doors with the key.

Did I mess up a sensor or something? Does anyone know if there is a way to reset it? What should I do?

Thanks!

NM

[nightmoon]

Note: I just tried disconnecting the battery for a few seconds to see if that would reset anything. Didn't work.

[nightmoon]

Based on everything I've read, downloaded, searched this forum, etc., I think it might be the courtesy switch in the rear door. Does anyone know were that might be? Thanks!

[cduluk]

believe they're "internal", somewhere in the latch mechanism. They're not just a small rubber boot somewhere along the rim...

Try taking the mechanism piece apart in the tailgate and see...

[nightmoon]

ok. Thanks. Now how do I go about taking it apart? What am I looking for and how will I know it when I see it?

Thank you!

[cduluk]

Honestly, no idea. But if you open it up, if you see any wires going into it, it will lead you to the switch, just not sure which switch type they use.

I don't own an rx300 anymore so i can't look, but you'd either gain access from the outside or you'll have to remove the back cover of the tailgate. By money is on the back cover.

Open the tailgate. The inside of the tailgate is broken into two halves, the bottom covered with a "carpet" like shell, with a plastic type shell on the upper half adjacent to the rear glass.

Both of these panels are held on with only clips. So with a flat head screwdriver, try to pry the bottom one off. After it's off you just press it back in (did this before when replacing rear back-up bulbs) after you've done the fix.

After you have the cover removed, try and look for the latching mechanism. And you're gonna have to take it from there since i don't have an Rx300 here to check on. You can take pictures and post them here and maybe we can help further. :)

These are the covers i'm talking about

I took some pictures of the hatch interior panels removed on my Rx400h. It's a different model and design, but i'm sure the Rx300 still uses the same "idea"

[nightmoon]

OK. Thanks everyone for your patience and your help. Especially, you, CDULUK. Per instructions I removed the interior lower (carpet covered) panel in the rear hatch door. I followed the only wire coming from the lock itself to a junction just inside the panel. (see figure 1). Arrow on the wire points toward the lock mechanism.

Figure 2 pictures the lock assembly unbolted, the red arrow points to the other end of the wire from figure 1 going into the lock assembly itself.

Figure 3 is a picture of the lock assembly from the other side. The red arrow points to the wire going into the lock assembly. You can barely see it. Also note the position of the black ‘lock’ itself right in the middle of the picture. This is UNLOCKED.

Figure 4 is the same as figure 3 except the position of the lock in the middle of the picture (circled in red) is in the LOCKED position. This is quite easy to do by hand and this is the ‘hole’ I originally put the bungee cord into to secure the trunk lid while driving with that stupid piece of luan.

For what it’s worth, all doors will lock just fine from the driver’s inside control.

However, the dashboard ‘open door’ warning light does not go off. It stays lit and now on day 3 has drained my battery. The anti-theft alarm does not arm itself and the dome lights if set in the ‘door’ position, remain on. It’s my habit to keep these in the ‘off position’ all the time because if I leave the car door open for any length of time it has a tendency to drain my battery.

Just to repeat myself in case you’re not sick of me yet, when I try the button on the key to lock the car, I just get the warning signal that a door is open(lasts for 10 seconds or until I hit another button).

The back door actuator seems to be fine. Not sticking. It locks both from the drivers door lock button, or by inserting the key and turning it. All of the doors and windows will unlock (and roll down) using the remote keyless entry button on the key.

This is the part I think I need: http://www.toyodiy.com/parts/p_U_200001_LE...GKA_8424.3.html

One issue that comes up is if the part is the one I need and it’s the one pictured in my digital pictures I can only see the ‘clip’ end of it. The other end (or the wire anyway) goes into the lock itself which appears to be a closed system. I don’t’ see any way to take the lock itself apart to get to the part to replace it.

Your advice is greatly appreciated.

[cduluk]

Oh boy.

Yeah, the problem is definitely with the switch that determines whether the rear hatch is closed or not. If indeed that wire you pict'd is the only pair of wires going to the latch, it's most likely it (unless it's somewhere else?).

Try unplugging that wire, and connecting the two wires for a second (with a paper clip maybe), and see if the "open door" light goes out. There's gotta be a switch that's compressed when the hatch is closed, completing the circuit of those two wires. when the computer reads the circuit is closed, it knows the hatch is closed.

If the 'door open' light goes off when you connect those two wires, you know that's indeed the switch that's damaged.

[nightmoon]

You're the man CDULUK! Thank You! The paperclip test shut off the dashboard light. Unfortunately the car is as dead as a doornail. But not so dead I couldn't see the dashboard door open warning light go off.

My husband jumped it last night while I was making dinner and it was my intention to drive it around for 20 or 30 minutes afterward, but he thought he'd do me a favor and drive it around for me. I later found out he only drove it twice around the block which didn't charge squat.

I have a board meeting to go to this evening and it will take 30 minutes to get there. I'll get a jump before I go and it'll be ok sitting for a short couple of hours and tomorrow I'll make my next move.

I probably need to get the part ordered. It's only a $25 part from Irontoad.com.

Next I need to either figure how to get into the latching mechanism to replace the part. There must be a way in or they wouldn't sell the part separately, don't you think? Does this make sense to you?

OR

I need to take these results to my mechanic and let him put the part in for me. I dont' usually take my own parts to my mechanic but i think in this case he'll understand especially after I did all the leg work diagnosing the problem.

Just for fun, I read somewhere a long time ago, (Readers Digest?) taking your own parts to the mechanic was akin to taking your own eggs into a restaurant and asking "sunny side up, please"!

Your advice, as usual, is greatly appreciated, especially if you can tell me how to get into that lock.

NM

[cduluk]

Glad those were the wires, that's good news!

I'm not really sure how one would install the new part, but i'd leave it with the mechanic to do it... I suppose you could get the part yourself and bring it to him to install, i don't think he'd have a problem with that since it would just save him the time to have to find the part number, call in the order etc etc.

It seems like a complicates setup, with a lot of pulleys, cords etc, i've never done it before so it's hard to say the level of difficulty. In the Rx300 parts manual (i still have it) it lists the labor time it would take to install each part, and it lists the times around .2 - .5 hours which makes me think it might be easier than i think?

I'd still let the mechanic do it, even if he charges you a half hour's labor, if anything goes wrong in the future, you can just bring it to him and say, "Hey buddy, it's broken again!!" and it's out of your hands :)

[nightmoon]

That's awesome, Thanks!

I hate to do this, but a couple more questions if you don't mind.

It' will take a week or so to get the part shipped. I don't want to be 'down' that long with the battery constantly running dead every couple of days. So do you think it will hurt if I jury rig (i.e. duct tape) the paper clip into the plastic housing to keep it 'fooled' into thinking it's closed all the time, until i get the part and get it to the mechanic?

Lastly would you consider scanning and attaching the page where it says .2 to .5 hours to install that particular part?

Thanks so much.

Regards,

NM

[cduluk]

That's awesome, Thanks!

I hate to do this, but a couple more questions if you don't mind.

It' will take a week or so to get the part shipped. I don't want to be 'down' that long with the battery constantly running dead every couple of days. So do you think it will hurt if I jury rig (i.e. duct tape) the paper clip into the plastic housing to keep it 'fooled' into thinking it's closed all the time, until i get the part and get it to the mechanic?

Lastly would you consider scanning and attaching the page where it says .2 to .5 hours to install that particular part?

Thanks so much.

Regards,

NM

Yupp, you can leave the paper clip connecting the two wires for as long as you want (forever if you want). It's only simulating the door being closed so the computer shuts up for a while. When the door is normally closed those two wires are connected via the switch which is obv broken for some reason.

Here's the manual that shows the part numbers, dealer cost and labor time :)

[lenore]

cduluk you are truely a asset to this forum. You spent time and worked through the problem in a logical manner....Well done....

[nightmoon]

Thanks again, what can i say? You're just awesome.

I jury rigged the paperclip. Now waiting for Husband to get home to give me a jump to go to my meeting and it's POURING cats and dogs... darn it. Time will tell if this will get me where i need to go. Or at least keeping me from going into dead battery mode.

Heres one thing that i noticed. On the picture you posted of the lock and hardware, and times to install, the part i thought i needed to order isn't there.

Here's a picture off Toyodiy.com

http://www.toyodiy.com/parts/p_U_200001_LE...9.html?hl=69350

of the back door, lock and handle. These are the parts that are in your picture.

The part I thought i needed is listed under electricl/anti-theft section, to wit: http://www.toyodiy.com/parts/p_U_200001_LE...GKA_8424.3.html

It is part 84903-48010.

I'll check back later. Thanks for letting me know if you find something.

Regards,

NM

[cduluk]

thanks lenore :)

Nightmoon, i'm not really sure which specific part is defecting here, it's hard to tell. The Lexus part diagrams are ALWAYS difficult to understand, and they vary by publisher. The one from the paper manual i have and from Lexus parts is the same diagram with the same parts...

It seems the one you've found gets a little more specific though. By looking at the part you ordered, it looks like it's a part with the wire attached, so it's most likely the core issue. I can't even tell if the part in the lexus diagram maybe includes the part you got? It might be, you'll have to see when it arrives.

When your mechanic takes it apart, he'll be able to determine what exactly is broken. If anything, my guess is that the "switch" (the part you ordered) is the only part that's damaged since it's the only plastic part in the latch mechanism, which is softer than the metal surrounding parts. I doubt you could have damaged any of the larger parts just by attaching a bungee cord to it. The switch (part you got) should be able to replaced when the mechanic takes it apart.

Worse comes to worse, your mechanic will find out what else the problem is... He'll be able to determine everything once the latch is opened up. The important thing is that the paper clip is completing the switch's circuit for now so the computer thinks the liftgate is closed so the battery does not go dead. The switch really isn't... an "important" safety etc related thing, it's just cosmetic. The car will function just fine the way you have it now, you just won't have the luxury of knowing the hatch is open... Having the switch is just a convenient thing to have to notify you via the gauge cluster by that little red light, that the liftgate is open.

Let us know how everything turns out! :)

[Kauz]

I ran into the same issue on our 2000 RX300.  The door ajar light on the dashboard would stay lit even after all doors were shut and the lift gate was closed.  When I tried to lock the doors with the remote or using the button on the driver door the doors would lock and then always immediately unlock.  The only way to lock the doors was manually at every door or using the key in the door, turning towards the front of the car.

Based on this thread, I first checked the lift gate, but that wasn't the problem.  I disconnected the connector shown in Figure 1 above, and the resistance across the two wires going into the back latch was zero (short circuit) when the gate was open, but became infinite when the gate was shut.  This was contrary to the solution that was stated above on this thread.  In any case, the switch in the latch seemed to be functioning.

Next I checked the window/door lock module on the driver door.  I had a spare module from the past with a broken window key, so I removed the module (look on youtube if you've never done it before so that you don't break any tabs), disconnected the module and connected the spare module.  The door ajar light was now going off when the door was closed and I was able to lock the doors as normal with the switch on the door and the remote.  So, this proved to me that the problem was with the electronics inside the driver door switch module.

I also realized that this issue surfaced when the weather got close to freezing here one night.  It could have been a coincidence but also could mean a cold solder joint on the circuit board inside the module which could have resulted in an open circuit when the temperature dropped.  I removed the three large screws and the three smaller screws from the plastic housing on the back of the module, removed the plastic covers, and removed the circuit board.  Examining the pins on the two ICs (Integrated Circuits) to me it seemed that a few of the pins were sitting a bit too high and perhaps not making contact with the solder pads underneath.  Using a soldering iron with a fine point I carefully touched all the pins one by one with very little pressure and without any solder on the iron tip.  I was only reheating the pins and lightly pressing them on the solder pads below.

Next, before putting the module back together, I took the circuit board to the car and plugged in the connector.  Sure enough, now the door ajar light was functioning properly and everything was back to normal.  I put everything back together and reinstalled the module in the door.

Keep in mind that a broken wire or a bad sensor inside one of the locks could also result in the same symptom as I was experiencing with my car.  So, there is no guarantee that your car has a bad door switch module, but it may be worth a try.  It's too bad the RX300 does not indicate which door is not closed.

[Drew22]

Snap off back inside panel and snip two wires which run through a blue cover. The wires begin at a plastic snap connector and run into the latch.  Avoid cutting the wires that run to the motor which actuates the latch. Voila, No more idiot light (do you really need it?), and no drained wallet and/or battery.