Red97tj

Currently my 08 w/ Nav & ML stereo is having issues w/ the climate control system. When I start the car the Auto climate control button light is on but it goes through that diagnostic check where there's nothing comes on until 10-15sec later. I've checked all the known threads of recirc door falling out of track, broken door, etc. & I don't have that issue (I took the glove box off to confirm this). The interesting issue is sometimes when I start the car, I can see the recirc door open/close a couple of times like it's going through a diagnostic sequence (I can see this since I leave off the plastic covers inside the glove box). And sometimes I can open & close the door by pushing the fresh/circ button until it goes haywire. So I have a feeling that the climate control computer is probably the issue.
My question is, does the center console climate control panel controls the recirc door? Or is there a separate computer module that's mounted somewhere near this area? I want to buy a used one to see if it can solve this issue.

Another issue that happens infrequently. The steering wheel volume control does the opposite of what the button supposed to do (push button to turn volume up & it actually goes down). It has happened twice since I've bought the car in Feb. And just the other day all of the sudden my stereo just turns itself off & just shows the blue speaker pic when it's off. I tried pushing the power button a few times but nothing happened. I finally got it to turn back on by pushing the Mode button on my steering wheel to get it to turn back on. Has anyone had these problems before? And what was the fix?

Thanks in advance for your help/input!

Red97tj

No one has any info??

sha4000

iTrader: (1)

You must be talking about the AC amplifier. It's on the passenger side right where the passengers left knee would rest. You have to remove the glove box to get to it.

DavidinCT

Have you pulled the battery and let it sit for a 1/2 hour to see if that helped ?

Sounds like your have some screwy issues... Is this a new car to you, what type of history does it have ?

Red97tj

Thanks for the info. I'll see if I can pick one up on Ebay...
FYI, I have a/c self diagnostic codes 21, 24, 42. Is there a way to clear it manually w/out having the Toyota service program? I'm curious if they'll all come back or not.


Yes, I've done that...I changed the spark plugs last weekend & took out the battery to get access the coil/spark plug. It didn't affect the climate control issue. Not sure about the other audio gremlins since they're intermittent.
And yes the car is new to me. I bought it back in Feb. so I don't know if that was a problem to the old owner. I suspect it is but maybe he didn't care about it.

Thanks for the replies guys!!!

DavidinCT

If you have a old laptop around (Even a old Windows 7 laptop will do fine)…. Go on ebay and buy a $15 set with Techstream with a cable. Follow the directions on install.

Its a very worthy tool to have on a Lexus... This will take care of all your codes and is an official software that Toyota/Lexus uses. You can even add keys(according to other members), and tweak features in the car with it, and NOT needing to see the dealer for them.

Otherwise, if your just trying to clear a "check engine" light, go to one of the places that lets you check codes and see if they will reset it for you (like pep boys or one of the auto part places) or for about $40-$75 buy one...

Red97tj

Thanks for the Techstream suggestion. Just ordered one on Ebay.
And yes I have a couple of things to clear engine codes. I have a knock-off ELM3237 bluetooth along w/ my Autel reader. Luckily she's running like a champ so hopefully it won't be needed for a long while.
If I can get the electronic stuff taken care off, swap out suspension bushings, and change out the trans fluid/filter, I'll get to just enjoy the car then.

213374U

Just a thought, but have you made sure the cabin filter itself is seated properly? This too can cause the same issues we see when an issue with the recirc door crops up.

Red97tj

Sadly I wish that was the problem...the filter is sitting correctly.
I ordered a used AC amplifier from LA on Friday already. Once I receive it in a couple of days, I'll update everyone if this was the problem.
Thanks for all the replies.

DavidinCT

Good luck !

Red97tj

Ok quick update:
1. bought a used climate control amplifier (88650-50442) which ad says it came from a 2008. The old one is (88650-50441). When I first plugged it in it gave me a bunch of error codes but after a bit of time, it adapted to the car. And again it gave me the 42 code which was like the old one. And it worked intermittently just like the old one.
2. bought a 2nd one (88650-50440) which is 2007. This one didn't have all those codes when I first plugged in. And then of course the recirc door was working perfectly so there was no code for a good day. I thought it was solved until the next day when the recirc door didn't work again.
3. So all 3 modules have 42 code which tells me it's the recirc servo-motor assembly that's the problem. I took the servo motor assembly from the fan housing yesterday & opened it up (I had to partially take the fan housing apart which I moved over about 1" so I can get a small philips head ratchet in there to undo the 3 screws). Tried cleaning up contacts & lubed all gears etc. Reinstalled it & it doesn't respond at all anymore. I just bought a used from ebay so more to come!

sha4000

iTrader: (1)

Please keep us updated. I was looking for a used amplifier also but can't find any with the correct part# 88650-50550.

Mbodall

It definitely sounds like something is wrong with your recirculate function, but the delay in operation of the entire system may be normal? In LS430s (and every other Lexus model I've driven including brand new model loaner cars I've driven), the HVAC system waits a good few seconds before kicking the fan on, and slowly ramps up the fan speed when it's switched to auto. This is especially apparent when the engine is cold and you have the system set to any kind of heat. It waits a little bit for the system to start to heat itself up so it's not blasting cold air at you from the beginning. I believe the delay is less, but it also delays and slowly builds up the fan speed when it's hot out and set to A/C. Same sort of thing, it's letting the A/C compressor to start circulating refrigerant so it's not blasting piping hot air in your face.

Has this always been an issue since you bought the car, or is a new problem? If you manually set the fan speed, does it start blowing air immediately? Or does it still make you wait 10-15 seconds?

Red97tj

Ok, finally got the car fixed!!! The car remembers my old temp setting along w/ no more diagnostic mode when I first start the car. It makes a huge difference when I get into a hot car & the AC starts right away...

Alright onto the problem/solution:
The servomotor assembly for the recirc door was bad (as the code 42 suggested). The problem was the potentiometer that's inside the assembly. I bought a used servomotor from ebay (063800-1030). I took out the potentiometer out of that one & installed into mine just to confirm that was the problem (only 4 screws & few plastic tabs to undo these so not a big deal). I guess w/out the potentiometer, the car doesn't really know where the recirc door location is at so it goes into diagnostic mode. Interesting side note, as I was removing the servomotor, I saw 2 additional servomotors on the HVAC system itself that's exactly the same thing, only they were visually obscured by plastic coverings.

Here's a couple of suggestions for part removal:
In my early post, I said that I took the blower assembly apart to get to the servomotor. I couldn't take the whole assembly out of the car. I was only able to slightly lower it along w/ sliding towards the passenger door to get me an additional 1" or so, and that was enough space to get my hands & used this Harbor Freight right angle ratcheting screw driver:


It wasn't a walk in the park because you'll need to man handle it to get it out & to put it back in. So the 2nd time when I need to remove the servomotor, I thought I'll try something different. I went to Home Depot to find the smallest right angle drill adapter. I found 2 (Milwakee & Dewalt). The Milwalkee is the smallest one but the head is 105 degrees so that didn't work because the Phillips bit is a bit cocked (there's not enough room in the car). The slightly larger Dewalt one is 90 degrees which is perfect:



With a bit of patience, I was able to remove the 3 Phillips head screws from the servomotor. When I went to reinstall it, I got lazy & only put back 2 screws which was sufficient.

@ sha4000
What year is your car? The 3 amplifiers I have on hand does work no matter what. The number doesn't really matter. I think vehicle generation is what matters more. I spoke w/ the HVAC manager at work (I work for an automotive OEM...not Toyota) & asked about this black box. He explained to me the Toyota is smart to use these amplifiers. They use the same actual black box across the different vehicle line, only difference is coding for that particular vehicle. The push buttons on the center console are just remote buttons which send signals to the amplifier & the amplifier carries out the actual functions.
Most of the other OEM has the box be part of the dash assembly, so pretty much each vehicle will have different controllers because of center console shape, options, etc.

Anyway hopes this helps anyone who's struggling to get their HVAC system act correctly...

sha4000

iTrader: (1)

Good work. I gave a 2007, it's in my signature. I have the rear seat HVAC so I don't think any odd amplifier will work. The actual number on the one in my car is 88650-50450 so I don't know if that has been updated or what.