Technical Climate Control Problem [and Fixing Guide]

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Technical Climate Control Problem [and Fixing Guide]

Stilo Belgrade

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Hello everyone!
I am new here, but have had a look at numerous posts on this issue, but none addresses my problem exactly, so here it goes:

I have a 2002 Stilo 3dr 1.6 Dynamic LHD with Dual Zone Climate Control. My climate control has the following symptoms:
1. Blows hot air on the drivers side regardless of the setting and temperature control functions well on the passenger side.
2. Temperature control appears to functions well on both sides when in Air Recirculation mode.
3. Air direction setting does not seam to make any difference. Dashboard vents are always open, therefore low foot well and windscreen blow.
4. Blower fan behaves as it should, i.e. no intermittent play as many of you experienced.
5. Compressor kicks in OK and the system is well gassed as the passenger side gets ice cold.
6. Intensity of the blower is excellent and fully controllable from light breeze to hurricane speeds, so I guess the filter is ok too.
7. MONO or DUAL, AUTO or FULL AUTO does not make any difference in described performance.

What I did so far:
1. Read most of the treads here.
2. Tried "reboot", "stop and go" and "re-learn" procedures. They sometimes make the difference, but most of the time the performance stays as described above.

My questions:
1. Am I looking at dash dismantling to be able to solve my problem?
2. Is there anything else I could try that doesn't involve the procedure from my first question?

Thank you all in advance!
 
Hi,

It seems to be the bosch control module near the feet vent or some broken plastic gear.
I'm having the same problem and I figured it out because it started to do some wrecking noise and emitted vibration. I've dismantle the plastic cover on the driver side and found that bosch module. You can move the gears by hand and test the flow direction and/or the air temperature on the vents. Remember, dualzone climate means two independent circuits and modules, so, one of the modules must be wrecked but it would be very unlucky to have the two bad.
Put on dual, put front vents, put let's say starting temp on 18ºdegrees, start rotating driver knob...did the temperature rised? If no, do the same thing on the passenger side, one should work.
Next step, move the gears gently and see if something is happening.

Good luck!

RJ
 
Hello Jose,
Thanks for the quick reply. I will try what you suggested as soon as I find some spare time.

Regarding the dual temperature setting and flap actuators, I will try your procedure.

Let me just mention again the fact that it is not possible to select the direction of the airflow (this is mutual for both zones even though that it is dual climate control). It always blows through dashboard vents, no matter what the setting is. So, is it also possible to access these actuator gears as well when side panel is removed?

Also, I can almost always hear a faint noise from the dashboard. It sounds a bit like: Bzzzsssss-Bzzzsssss-Bzzzsssss... I hope you can imagine that sound... It is very faint, even the normal ventilator noise "covers" it... And it is NOT coming from the ventilator...

Thanks again!
S.
 
I know the symptoms and unfortunately I know the buzzing. The buzz is a constant, even if you turn off the ventilator it will keep buzzing, altough it's a very discrete sound.
The bosch module is trying to move the flaps and ensure the mix between cold and hot air to give you the temperature you requested, but somehow one of the plastic gears must be broken (usual stuff) and it's stuck on that position. I know you're not getting the direction you request but select front vents anyway. Start at cold air (with the engine at warm at least, best at 90º), and push the temperature on driver selector gradually, see if the air temperature changed.
If your case is similar to mine one of the vents will pump slightly (at least) different temps, and the other one will always pump the same temp.

The diagnosis is, probably you'll have to buy the module, quite expensive :( but meanwhile you can, with some pacience, put the module in a position that you can have 80% of the features running ok. With luck maybe it's just stuck and you push it to work.

If you have trouble finding the gears post, I'll try to get some pics.

Regards,
RJ
 
I think you had the same problem as I do now. I will get to it this weekend, and will let you know ASAP. Until then do not waste your time taking photos. I think I will be OK without them too.

Thank you!
 
I had a quick look this evening on the parking lot. As it was getting dark I only removed the low part of the centre console (on both sides)... These are the bits of plastic that have the ducting for foot-well air ducts. I was able to see up and behind directly at three white gears. Whatever I did to the climate control they didn't move at all. All this was on the drivers side (LHD car). On the passenger side, I was only able to see some sort of a white joint in the shape of the mirrored "L". This didn't move either.

During the test, it played up in the manner it had never before. The passenger side was blowing only ice cold, and the driver side was completely controllable. Again, only blowing through the dashboard vents as it did before. Windscreen and foot-well almost nothing.

Now I guess I have to remove the upper part of the centre console, but this seem to require the removal of the climate control unit, lower glove compartment, the console between the seats including the arm rest... is this correct and is there anything else that I will have to remove?

Regards!
 
Hi Belgrade,

I see you already figured out where the problem is... on the passenger side.
Yap those are the gears that I was talking about. Your problem seems similar to mine so I'll explain to you what I did before you start to break the car apart :), I don´t think there's need for that.
When you have time take the passenger side lateral plastic cover, like you did, look up and find that 3 gears, move your eyes down and see if can find a small black plastic box from Bosch, you will see wires coming in (power wires), there sits the problem why you can't get climated air on the passenger side, it maybe stucked, nevertheless try to rotate one of the white gears with your hand, the one to rotate is the one that is half a gear, kind a bit less then a half gear, I think it's the first one you see. Rotate it gently from the point where it is for one of the maximum points up or down. Then try your climate, see if you have directioned or climated air. Try it on several positions, and always check if it moved. You only need to do this on the passenger side since there is where the problem is.

If you get results then it's the bosch mechanism, you got to buy one, but no need to take any more panels :p

Regards,

RJ
 
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Thanks for your input RJ.

This thread describes my problem aswell, and it seems to be very common. Since I drive on the right side, I have the steering wheel on the left side. :p

Anyway, the hot side is the driver's side and it's not fun at all. I also removed all those panels last year but didn't have a clue to look for. All those servos (looked like the servos from the time I had a Tamyia Hornet RC car) seemed to be working, but it might be the damn BOSCH thing. I will have to remove those panels again then... :bang:

Regards, M.
 
No prob Morty.

It seems that we share the exact same problem. I drive on the right lane too, so my driving wheel is on the left, and guess what, my climate pumps hot air on my vent too :D
The really annoying thing is that you can't turn on the air conditioned, it always pump a mix of our side hot air with the fresh cold air from the AC bahhh terrible.
I talked to a friend of mine, he is a car electrics specialist and it seems to be a common problem but not only on our stilos, also on mercedes and renault's. The most common problem is on that bosch box having wrecked gears inside. Months ago my box was stucked on cold position, that was ok, I could put only the passenger vent on hot and close mine, but now is stucked on hot, and the summer is coming, it will be unbearable. I'm taking mine out soon but before I will try to put it on cold again and then take the power off, if I can, then 100€ euros will stay in my pocket, if I can't, well I'll try to fix it some how.

I'll update this thread then;) If you need help please ask.

Regards, RJ
 
Hello all, I've got fresh updates to our issue.


This weekend I dedicated a morning to the climate problem, ok, the temperatures are rising up so, got to do it :)

MAJOR UPDATE:
The gears that I talked about on latest posts don't have direct relationship with cold/hot door switch, it was
coincidence/luck to rotate them to another position and the temperature changes.

So, first of all, if you guys don't bother to have your vent (driver vent) stuck on cold (summer and winter) then
you can follow the explanations and I ensure you to that will work. You always have the passenger vent adjustable on
cold or hot so, in my point of view, I'm keeping mine as it is, it makes no sense to buy another expensive module :(
If don't having one of the dual's affects your day, then, you can make the test too if you like, if you want temporarirly things working out.

Ok, I don't have photos because the place is a little crowded and my cellphone is very bad on close shots, but,
I'll describe the process and parts, and search for them one elearning when I have some time.

1- Take the plastic lateral (the one with feet vent) on the side with the problems.
2- Search for the Bosch/Magneti Marelli module below those 3 white gears. The module got some wire coming in, 5 wires on a plug.
3- Unplug the wires by pressing behind and pulling the plug. Take off 3 screws, they are gold colored, one of them can be hiding behing somes cables.
4- Take the module by hand. You'll see a part, where the module was connected, that seems like a arm, you can pull it up or down, but not like on/off thing, if it was you would only have two temperatures, freezing or melting :D
5- Pull the arm completely down. At this time you cand turn the car on and try it just to make sure. Pull it up and feel the air warming.
pull it down and see if the air gets colder.
6- You just have to let the arm down and try to hold it in that position somehow, I made it by twisting some wire over a screw.
Now, if you have time and you are curious or good about electrical stuff, you can open your module.
I'll sketch what's inside.

https://www.fiatforum.com/gallery/data/2631/bosch_engine.PNG




Sorry for the bad draw, made it fast on mspaint :p
If you put 12v on the two pins (pos/neg) the engine will go clockwise or anti clockwise, depending of course on the polarity you're juicing the engine.
If the engine its ok it will go from top to top without problems.
The problem of my box is, I think, on the 3 wires lefts. The car keeps feeding the engine even if it was totaly closed or open.
That made the gears start stressing and making some grinding noise.
I think that those 3 pins below are sending the car the signal off the engine position, like if you select 22ºCelsius, when the engine rotates the gears inside and make that position, those 3 pins send the signal to shut off the juice. Mine must be broken, so it is always juicing.
Correct me if I'm wrong someone.

Ok guys, my text is getting boring :p If you need some help please let me know. ;)

Regards
 
Fantastic drawing. One of the great things with Windows is Paint. :D

This is propably the solution to my issues. Are there two of these modules? One on each side, since I've got dual zone control?

It is anyway the left side that has the problem, feeding hot air.
 
Hey Morty, yes, if you have dual zone, then you will have two of these things :D
If you do the procedure you will end up with your side (the one with the problem) blowing ambient temperature air, with this I mean, direct air from the exterior. If you're in summer, the air will be hot anyway, you have to turn AC on of course, but on winter, the vent will blow ONLY cold air from outside, this is because you are closing the hot air entrance. The passenger side will continue to do the proper function, cold and hot, you are not going to do anything on the passenger side, only on your. The only disadvantage I can find is on winter, you got to close your side vents when trying to warm the car interior :p
 
Hey Morty, yes, if you have dual zone, then you will have two of these things :D
If you do the procedure you will end up with your side (the one with the problem) blowing ambient temperature air, with this I mean, direct air from the exterior. If you're in summer, the air will be hot anyway, you have to turn AC on of course, but on winter, the vent will blow ONLY cold air from outside, this is because you are closing the hot air entrance. The passenger side will continue to do the proper function, cold and hot, you are not going to do anything on the passenger side, only on your. The only disadvantage I can find is on winter, you got to close your side vents when trying to warm the car interior :p

That's great.

I actually think the centre vents (all 4 adjustable vents, 2 in the middle, 1 on each side) should only blow cold or "tempered" cold. All Fiats we have owned have had this behaviour - only cold feed at the centre vents. I asked Fiat why many years ago and they said it was a safety thing, not blowing hot air at the driver's face making him sleepy.

It would be great to have lots of time to fix this... I have no idea when to do it, but I will try to take some photos when working.

M.
 
I think you're right :D That's why I don't bother with my vent only blowing cold air, summer or winter. I can always manage to warm the car by selecting window vent or closing my vents.
The procedure is quite fast to take, the pain in the a** is unscrewing the 3 screws...

If you need some help guiding you trough the process let me now.

Regards, RJ
 
10122010113.jpg



Here you go fellas a nice pic of the culprit. Now of what i understand from your conversation the blue thing is what measures the open close values. but from what my electrician said this is a dual potentiometer in both directions. Logically this should stop working when it reaches a certain travel in either way. He said even if the gear sheared off (which happened to me) it should have stopped turning after the potentiometer gives a certain value. Now i havent gotten a replacement to test this theory.

Now can anyone help me with this stray plug i found while trying to solve this problem?

https://www.fiatforum.com/stilo/255951-climate-control-connector-help.html
 
Here you go fellas a nice pic of the culprit. Now of what i understand from your conversation the blue thing is what measures the open close values. but from what my electrician said this is a dual potentiometer in both directions. Logically this should stop working when it reaches a certain travel in either way. He said even if the gear sheared off (which happened to me) it should have stopped turning after the potentiometer gives a certain value. Now i havent gotten a replacement to test this theory.

Now can anyone help me with this stray plug i found while trying to solve this problem?

https://www.fiatforum.com/stilo/255951-climate-control-connector-help.html

Is this the servo from the defroster? Or is it for the flap for hot / cold?
 
morty i removed both of them because i discovered both my defroster flap and my dualzone left air mixture is problematic. this servo module has a servro and a dual potentiometer on the bottom this potentiometer changes the signal moving it around. the problem arises from this. how did i figure this out i will tell you how.

when i connected the defroster motor to the connector and just let it hang and watch the outside gear (where it connects to the flaps) the motor would turn counter clockwise for a bit then stop and go clockwise and wouldt stop.

THen i did the same with the left hand side dual zone motor and watched it. it went counter clockwise stopped then went clockwise for a very short bit and stopped. Pay attention though that the motor does have a protecting mechanism to not brake the inside flaps of the aircon in this even thats why you will see that on the outside of the motor there is a plastic protruding right beneath it. this blocks the gears from going more than a specific travel and the breaking of the gears is to protect the inside flaps i assume.

Anyways i ordered a set of gears and a motor but i didnt order a second motor because i believe i have found a way to fix it.

remove the top cover in this way so its less of a chance for you guys to break it.

removef.jpg


on the potentiometer (the blue thing) the top part black in this photo but i have seen it white on another motor.

cleanab.jpg


very gently stick a fingernail and make the slightest opening and spray some electronics contact cleaner (very important because it cleans and lubricates the connectors) then i did it a few more times around. start working the potentiometer turning it back and forth to get it clean.

in addition do not forget when installing back in to align the outside gear to potentiometer position correctly. if you screwed up i made a photo for comparison.

comparein.jpg



compareout.jpg


if the arrow of the potentiometer aligns with the line on it then this is how the outside gear should look like.

Connect the plug open ignition of the car (have clima off though) and observe if the motor is going in alignment mode, turning and stop in each direction. the bottom motor which controls the dualzone is easy since you can look at the outside gear touching each end of the plastic travel limit protector.

Anyways this isnt foolproof if the potentiometer is just plain shot. i will verify this on the clima when i get my hands on the outside gears which have been torn off.



Now all you lads in here hope you liked this and i need your help. my eper has no images unfortunently so i cant see much. i need someone to tell me if the defrost motor the upper most motor is the same with the lowest motor which is for the left dualzone flap.
 
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This was great information. I now understand why it is impossible to turn the servo from the outside - it has got these "technic lego" thread blocks inside.

I'll try to make some drawings right away, as I've promised earlier, about the top motor (defroster)... 15 minutes... (y)
 
The defroster actuator is located up into the dash. This procedure is for the LH Stilo. It must be easier with a RH Stilo, as the steering column and pedals are out of the way. The easiest access is to have a bench or something that is just the height of the door treshold, lie on it and slide in under the dash. Mount a flashlight up in the dash, and use a torx bit to undo the 3 screws. They are difficult to reach, an there is not room for tools. Use a leather or rubber glove and use your inner strength to unscrew the screws with the bit only. Before you start, unclip the power for the actuator.

left_actuators.jpg


The link between the actuator and flap is broken, and 90% of it is still located on the flap, but pulls out smoothly. See picture below. A little bit is stuck in the actuaor / engine / servo, and must be operated out surgical, with a scalpel or similiar.

The new link will only fit two ways into the actuator. I found it to be irrelevant which way. You'll see when you see the notches it has to fit.

But the new link will fit only in one postition at the flap. The two V shapes at the link will stop at the metal plate surrounding it. See the picture. This is what tells the actuator to stop. After years of colliding here, the link will shear, and the flap stops rotating. The servo (actuator) though just goes on.

defrost_tannhjul.jpg


To get this to work again, you first have to insert the link to the actuator. Position the defroster flap in the middle of the max/min (typed as "stop" and "stop" in the picture above). Use your fingers to rotate the white toothed wheel. Line up the actuator (now with link clipped in) so the two V shapes are in the middle, just as the picture. The actuator will most likely be way out of alignement, perhaps upside down - far away from it's mounting holes. Do not use force, the actuator will not turn around if you try to rotate it. So you must plug the actuator to its power plug and watch it travel until it's about spot on for fitment. Unplug the power to it, and tamtaaa, it will fit up there without braking anything. You can now rotate it a certain degree back and forth, but not much, as the link will stop in the metal plate.

To prevent the torx screw to constantly fall out of your torx bit, use a bit of used chewing gum as glue.
 
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ok i think me and morty just gave the most thorough guide ever on fiat forum anyone do the honors to write it up? lol


Also someone please look up if the defroster servo is the same with the dual zone distrubution servo im strugging to figure this out on the eper.
 
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