anagramjones

it seems like most of the time i only get max heat (HI) or max cold (LO). all the settings in between don't do anything.

i looked at the heater control valve, and removed the cable that controls it. the valve itself seems to move pretty freely.

so perhaps the cable that controls the valve is not moving well? anyone have experience with this or replaced the cable?

thanks

Vlad_Type_S

iTrader: (3)

Start by seeing if you have any HVAC DTCs.

anagramjones

ok, so i tried to follow the instructions and this is what happened, i don't have NAV:

1. Displayed Hi, fan blow on lowest setting through windshield, lasted about 30 seconds
2. Displayed Lo, Auto and the fan blew very hard, lasted about 30 seconds
3. Fan turned off and no code showed up...unless i was still supposed to wait

that's why it seems like a mechanical problem?

on Lo, i get cold air. on Hi i get hot air. the settings in between usually don't have a bearing on the actually temperature of the air.

when i look at the heater control valve, this holds true. it will go from all open to all closed..usually won't stop in between...

DeathMetal

iTrader: (2)

Although a cheap means of troubelshooting, I'd recommend replacing the heater control valve and the cable. Both are susceptible to hang ups via debris over time and cna prohibit modulation.

I've replaced both as noted with favorable results.

anagramjones

yes, as i recall there's a DIY for the control valve. in fact, i even bought the parts, just didn't get around to changing it last year but weather's getting nicer again and will try.

when i unhooked the cable, the valve seemed to move very freely, so i suspect a problem with the cable.

do you have directions for the cable? i can't figure out where it leads to. is it hard to replace? i want to replace the cable but don't know how.

thanks!

DeathMetal

iTrader: (2)

I had meant to capture images for a DIY but was in a bit of a hurry at the time. The cable attaches to the control valve in the engine bay and terminates at the actuator behind the driver side knee panel. Simply disconnect at both ends and thread the new cable through by attaching the new cable to the old cable. Shouldn't take more than 30 minutes including recaibration.

Shoot me a PM if you need help upon the time of install, I'll give you my #

anagramjones

i'll send you a message after i've looked more carefully at where the cables go and probably need some more guidance. you make it sound so simple...last time i checked, i didn't know how to see/access where the cable terminates "at the actuator behind the driver side knee panel" and i don't know what the procedure is to recalibrate the cable.

planning to give it a look this weekend during the Victoria Day long weekend (Canadian)

DeathMetal

iTrader: (2)

I'd recommend the trifecta. Once you've removed the knee panel, you'll see it. It's easiest to see if you're lying on the driver seat and working upside down, IMHO


- REPLACE HEATER VALVE
https://acurazine.com/forums/showthr...ighlight=valve

-REPLACE CABLE
(See above)

-CALBIRATE



-CALBIRATE

anagramjones

i'm hoping i won't need to replace the valve and hoses..even though i already bought replacement parts..because that doesn't seem to be the problem.

when i disconnect the cable from the control valve under the hood, the cable doesn't seem to move unless the temperature setting is either HI or LO (occasionally i get in between angles) but usually just fully open or fully closed.

i wonder if the actuator is working properly. i might have a better idea when i figure out how to access the driver's side knee panel and look at the actuator.

otherwise, as you suggest, maybe the cable is sticking or something.

doesn't appear to be any leaking coolant, so hopefully that means there's no leaking from the control valve tubes?

Slpr04UA6

^when my heater wasn't working, my mechanic and I went troubleshooting. Found out the cable wasn't moving the heater control valve.
Popped of the black panel above gas/brake pedal, and the little black box where the cable connects, is just above the gas pedal (on the knee panel side). We removed the black box, and for some reason the cable had slipped off where it connects to the mechanism behind the black box. Reattached the cable, and all has worked great for a couple years since. I believe there are a few 10mm or smaller bolts to remove the little black box (if I remember corectly, you can see the cable going into this black box). I didn't have to remove any drivers side knee panel.

DeathMetal

iTrader: (2)

There's no need to replace the hoses.

Which would indicate a stuck cable. They are prone to debris accumulation in the sleeve.

There's a diagnostics mode for the valve as well.


Where there's smoke, there's fire - if you're not seeing coolant, there's no leak.

anagramjones

ok, so i went digging under the steering wheel and figure out how to pop off the lower dash panel. actually this was not necessary to see the cable actuator (picture), but removing the panel gave a better view and more access.

i don't think there's anything wrong with the cable either. i think the actuator is jammed by dust and other debris (circled in red). the actuator seems to be made of a group of plastic gears, which i assume is controlled by an electric motor somewhere?

i watched the actuator as i changed the temperature from LO up to HI....i would expect slight movement with each increment of 1 degree C, but it doesn't move for several degree changes, then it moves a whole lot.

i did that diagnostic and there were no codes, so i'm thinking this means it's not an electrical problem?

i guess it might still be the cable, but the gears look pretty obviously dirty. and that bunch of dirt in the picture is actually jamming one of the gears, i noticed.

are there any diagrams or an actual part name/number for that actuator?

i'm going to try and clear it, but it's hard to get to and i started getting a headache from lying upside down, haha. i'd need a long piece of metal with a hook...maybe take a wire and bend it, try to clear out some debris? hold a vacuum close by? the grease will hold onto lots of the debris though..any ideas?

i would have gone further when i inspected it, but i'm a new father to a 4 month old and when mom needs help, i've got daddy duties to perform.

do you know what the part number for the cable is?

thanks

DeathMetal

iTrader: (2)

Congrats, my man! My second one is but 3 weeks old, it's a trying time!

Part #16, 79544-SDA-A20 CABLE, WATER VALVE CONTROL

anagramjones

thanks! congrats to you too!

so i removed the air mix control motor, left it plugged in while adjusting temperature from LO to HI to see if it moved properly.

(aside: the plastic gears themselves, while dirty, do not seem that obstructed...but maybe it all adds up...ideally i'd remove everything, clean them, put new grease on...will have to see if i have the time)

so it seems that the air mix control motor will not rotate at all for several degrees, then when i get to about 25C, it moves a lot, then move incrementally up to HI....this makes it seem more like there's something wrong with the control motor....unless the electrical signal from the panel is wrong, but i didn't get any DTC codes...

also, i was trying to remove the mode control motor (above the air mix control), but the bolts are hard to access, will have to try again later. anyway, while left in place and plugged in, i noticed that it does not move at all except between 22 and 23 degrees C....that doesn't seem right either....

but i think i'll have to remove the motor form the gears to determine if the gears are sticking, or if its the motor that's unresponsive....and again, perhaps it's the electrical signal (though no DTC codes)...

frustrating...when you look at the motors from under the dash, do they move incrementally as you change the temperature through the entire LO to HI range, or do they move only at certain temperatures?

thanks

ps. will try to get photos later

anagramjones

ok so i removed the air mix control motor. it controls some gears that seem to adjust a black gear that's attached to the blower behind the dash, which is weighted and rotates down by itself; it also controls the cable leading to the heater control valve

anyway, the white gears looked pretty dirty, and when i moved the gears around manually, they appeared to get stuck half way. i think it's perhaps because the grease has gotten old over the years, and turned sticky and slightly solidified. hopefully it's as simple as that. so i removed the white gears controlled by the air mix control motor, and i'm going to clean them and apply new silicone lubricant and reinstall...hopefully this makes it smooth...of course, maybe the motor is just weak and dying...but i'll try this first.

i also wondered why the mode motor (above the air mix) didn't move through the whole range of motion. for one thing, i realize now that i was adjusting the wrong button...instead of up/down temp, i should have been pushing the 'mode' button.... i actually also got under my wife's 08 accord, and noticed that the motor doesn't move with every degree change either, and her car is pristine with 44,000km on it...so i guess that means it's normal...

furthermore, i don't really have a big issue with my mode selection...it's more or less working fine...the floor vent is kinda not great, but it's serviceable. in picture 3, i actually removed the mode motor as well (pain to get the screws out)....and then i noticed that there are actually 4-5 white gears controlled by this motor...underneath a metal bracket, underneath a slew of other components that are tightly packed around the steering column....

i realized that this was a far as i could go..at least from this direction. being upside down too much is no fun. so much as i wanted to remove all the white gears, and clean them and put new grease...the stuff behind the mode motor is just too hard to get to..and since the mode setting is still working, i put the motor back.

so just focusing on the air mix motor and its gears, because that's my actual problem....no control of hot/cold through the range...

i also ordered the cable that controls the heater control valve...it's like $10 up here in canada, but whatever. i figure i want to minimize any friction, so hopefully i'll get the full range of selection back again. i do already own a new heater control valve, but i checked the one in the car, and it's pretty freely moving so don't want to mess with it...

hopefully when i get everything installed again, this will solve the problem!

anagramjones

ok, so i've cleaned the gears that are controlled by the air mix motor. attached a picture in case anyone's interested. i'm planning on reinstalling them with new lubricant. i got a tube of Permatex Ultra Slick Multi-Purpose Synthetic Grease. hope it's good stuff.

i also received the new cable to that goes between the air mix motor and the heater control valve. i think it's smoother than the one that's in there now...so hopefully the combination of all this cleaning will make the system smoother and fix my problem.

dcmodels

Honda does recommend a specific grease for HVAC plastic gears. You can read about it here. Its expensive and there are alternatives, but a gease compatible with plastic should be used. A common grease like White Lithium is petroleum based and will damage plastic. I don't know about the Permatex grease you have named, it may be OK:
https://acurazine.com/forums/showthread.php?p=13884378#post13884378

anagramjones

dude! where have you been the last year of my life? i need to check out the forums outside of TL to get all the goods on DIY and repairs.


the lube says it is safe on plastic...it's 95% trade secret and 5% PTFE...useless details..can't find an MSDS or TDS, seems older, not even on the website...

stuff is harder to find in canada...sheesh. and i can't even find the molykote anywhere...

and you can bet it'll cost like $40 for the lube from honda/acura...which...on principal, i can't shell out... and if it only has a 5 year shelf life..that means this needs to be lubricated several times in a car's life..no one mentions that, including acura...at least make it more accessible!

anagramjones

OK, so i'm pretty anal and i called acura and honda anyway about the lube cause i'm a real OEM kind of guy..haha....

honda doesn't carry it, otherwise it's $25. any thoughts about whether the OEM stuff is probably the best stuff to use?

the cost i was expecting...it'll take a few days go get shipped in cause none of the dealerships around actually carry the stuff. i was hoping to do this this weekend though....boo

anagramjones

ok, so after looking into it some more...i'm going to have to go with the OEM grease....much as it pains me....if for nothing else, than its shelf life. apparently the molykote has a 5 year shelf life, permatex and that super lube all have 2 year shelf lives...

now, hopefully i'm not getting a really old tube when i order it from acura because they said it's the last one, and they have to get it form their warehouse, so it'll take a few days. but i guess it's still more assurance than 2 years....

i don't want to have to re-lube this too often, because all the screws are self tapping and i don't want to damage the threads in the centre console. hopefully i'll have moved onto a TLX before this needs to be lubed again

so reinstallation plans for this weekend are dead. but i did buy a new cable for the heater control valve, so i might install that.

DeathMetal

iTrader: (2)

None so far have done what you're doing, so keep posting...this is really informative.

anagramjones

OK, so I asked dcmodels how to decipher the date code on the grease. he was kind enough to share a VERY informative post that he made, along with his reply:

There probably be two dates codes: one on the actual product, from Dow Corning. I don't remember the format. And one date code on the Honda external packaging, as indicated in the link above. If i remember, the two dates were around 1-year apart.

https://acurazine.com/forums/1g-rdx-diy-faq-161/how-read-oil-date-codes-775691/

so i just picked up my tub of grease from acura today. pictures are below with the two codes.

still not exactly sure how to read these codes, or which one is which, but my guess is that it was manufactured in 2011 (boo) and Honda picked it up in 2013 (still boo). it was the last one they had in all of Canada apparently...what're you gonna do? i'm going to use it anyway, hopefully it'll last a little while anyway.

dcmodels

H013077 likely means Honda 77th day of 2013, and appears to be a sticker applied by the Honda dealer, or Honda distributor. When I purchased my own tub of grease from a Honda dealer in the USA, it was contained inside a standard Honda plastic baggie/ package, with the date code format (JD - 10354) as indicated in my link above.

QK119095 printed on the tub itself by Dow Corning. Not sure how to decode that, and manuf often use obscure date codes on purpose. I will check the date code on my own tub, which gives me two samples, and may give me an idea of how to decode.

anagramjones

fixed the problem!

so i finally had a moment to put things back together. i went ahead and used the molykote grease, but i noticed that the grease is a little tacky, especially when there's too much on the plastic gears. in this respect, a cheaper store brand (permatex) MAY have been a better choice, i'm not sure, i didn't use it, i stuck with the molykote from honda.

putting things back together was a huge pain, even more so than taking it apart. this is because access is so horrible down there, not because the concept of the gear motions was hard to grasp.

first picture shows the two white gears replaced with grease in key areas. i think the white one on the bottom was the biggest offender. it contacts that black gear, which rotates down by itself due to gravity. without the air mix motor attached, this white gear is pushed into the lower position (pictured) because the black one rotates down automatically. i noticed that when i tightened the screw all the way (only snug), this prevented the white gear from moving all the way down. it would get stuck part way, so gravity was not enough to put it through the full range of motion.

i ended up loosening the screw quite a bit, in fact, there's probably a couple millimeters of play, more than you might expect. but the gears (white and black) are pretty wide, so they still maintain contact anyway. but i loosened the screw as much as possible so that the white gear moved freely, and the motion of the black gear was able to push the white gear all the way down by gravity alone. also, do not put too much grease on. maybe my grease was slightly older, maybe that's just the nature of the grease. but like i said, the grease felt a little tacky and you could hear the grease sticking/unsticking. so i wiped some grease away, and the result looked like much less greasing than what the car originally had. i think that overgreasing and subsequent breakdown/additional tackiness of the grease over time contributed to this problem to begin with. white gear at the top was freely moving, again don't overgrease.

picture 2 shows the motor replaced. just a matter of of putting things together. highly recommend socket with magnetic end for philips head screws/bolts....i didn't have one, big pain in the butt. i screwed the bolts and screws in by hand first, then tightened with ratchet and 1/4 inch socket and philips head bit. weird postures. very frustrating. the bolts are 8 mm, but i found it hard getting in there with the ratchet. the longer screw head allowed some more clearance.

ok, so i also wanted to change the wire from the air mix control motor to the heater control valve. it adjusts how much heating is transferred to the ventilation system by adjusting the amount of coolant that passes through the valve. i noticed that the new part moved much more smoothly. as suggested, probably debris buildup over the years.

picture 3 is a view of the heater control valve in the big red circle on the left, from under the hood. the small red circle is where the cable roughly enters into the cabin through the fire wall.

picture 4 is a close up of of the entry point for the cable from under the hood. it's at a weird angle, so the top of the photo is not actually up. but that rubber gasket that's circled is where the cable passes through. i've already removed the cable.

Tip: remove the cable by pulling it out from under the hood, not the other way from under the dash.

picture 5 is the same opening for the cable as seen from under the dash. again, cable has already been removed.

picture 6 is zoomed out to give you an idea where the opening for the cable is. it's just above the air mix control motor (black box with the smaller green 5 pin connector on the left).

after you pull the old cable out. take the new cable and push it through the rubber gasket from under the dash. push out towards the engine, not the other way around. don't be afraid. there isn't too much resistance.

last picture if a picture of the overpriced (well, maybe not) molykote. wasn't really what i was expecting, but there it is. i don't know what i was expecting..maybe not so empty. and the tub was labeled 40 grams...when the part is supposed to be 90 grams...got totally ripped off.

anyway, so i put everything back together, reconnected the cable on both ends, and cycled through the temperatures from LO to HI, which goes from 19 degrees C up to 31 C.

before, the gears controlled by the air mix control motor would not move for several degrees, and often just get stuck on either LO or HI. now, it moves incrementally through every degree in the range. i heated up the car a little and indeed, i finally have some moderate temperature air blowing when i set to the middle temperatures. in the past, i could have it set to 23C and it would be piping hot because the control was stuck with the valve on 'hot'.

i posted before that there was no electrical code, so i figured it was mechanical.

i don't know if changing the cable alone would have solved the problem. perhaps that change would reduce the friction in the system enough to restore functionality. but i think in my case, the gears were sticking together because of the old grease.

i've heard people with temperature problems. so hopefully this is helpful to some of you who might have the same issue that i had.

this is the order i'd do things:
1. check for DTC codes before doing any of this stuff to see if it's electrical (see post above).
2. change the cable
3. then, if that doesn't fix it, remove the motor and check if the gears move freely.
4. if not, they might need cleaning and new grease.
5. plug the motor in while it's removed to see if it moves well, if not, the motor might be damaged.
6. there's post somewhere in the 2nd gen TL forum where someone opened up the air mix control motor and re-aligned some gears inside and that fixed a mechanical issue. you might try that.

thanks for all the help from you guys!

dcmodels

My tub of grease has the same QK119095 lot code on it. I emailed Dow Corning w/ the lot code and this is their reply. I am guessing that "119" is "mmy". But that means for 2010 and after, the code will change slightly. Note that the email does not indicate how to actually decode the lot-code:

Hi Dennis,

Thank you for providing the lot number on the containers you have. Below is the information you requested.

Date of Manufacture: November 23, 2009
Shelf Life Expiration Date: October 28, 2014

Please let me know if you have additional questions by replying directly to this email.

Thank you,

Lesley Larson
Technical Customer Service
Dow Corning/XIAMETER
Phone: 1-800-248-2481

TRBOSVT

This thread has already given me a ton of insight on the issue I'm having with my '08 TL-S. I have had the exact same issue- the system is either HI or LO. While watching the heater control valve, it does just that- full deflection or none. When I ran the DTC on it, the system spit out a "K" and "I" code. Do you guys think this is a dirty gear problem in the "black box?"
Any insight on this would be awesome!

rubenders

I had this proble on my o7 tls last week I remove the air mix control and made the ac cycle from low to h with out the air mix being mechaniclly connected to the car just the power and is working fine now.

Irocwagon

Informative

TacoBello

Stirring up an old thread, as I'm having this same issue. Oddly enough, I disassembled everything underneath the steering wheel just to see what I was dealing with (OPs photos didn't help much), but once I put everything back, the hvac controls were working just fine! For a few days

so I'm thinking of replacing the old lube on the gears, but, I'm really debating if the moly grease is needed. Everywhere I read, they say moly grease is for high pressure, high temperature, metal to metal surfaces. These plastic gears don't cover any of those factors. While no doubt it's a super lubricant, it's hella expensive.

From what i do read, people say to use graphite lube for plastic gears... Can anyone comment?

scchevelle468

I did my passengers' side air mix motor 2 years ago and re-assembled it with white lithium grease on the white gears. Still working.

Jackass

I remember this thread...someday I will go through this process on mine to fix my lack of temp control....someday.....which I have been saying for several years now.