C4 Picasso 2015 (B78 plate) Heating problems

[domen2003slo]

Hi everyone,

i have big problems with heating in my C4 picasso...when i set driver side to max and passenger side to max, hot air is coming only from driver's right side panel (let wheel car) in the middle panel there is almost none heating, and on the right side from both air vents there's cold air. Cold air also blow from both rear vents.
Any ideas what could problem be ?

thanks a lot
Janko

[GiveMeABreak]

Hi Janko

You'll probably find that this is down to the air mixing flap motors. Depending on system fitted, there will be both air distribution and air mixing flaps. Sometimes the plastic cogs or the spindles wear out. So the motor turns the spindle to adjust the flaps, but where the plastic is worn, it just turns and can't move the flap - so the air mixing remains at the same setting (when engine warms up of course).

If you post your VIN up I can check the system you have fitted.

[GiveMeABreak]

I have your private message -

Have a look at this diagram and using the numbers, can you make it clear which vents are hot or cold when both left and right heating controls are set to hot temperature(when the car has warmed up of course).

This will help identify if it is the right or left mixer flap reduce that is likely to be faulty. Once I know this I will be able to put something together for you (possibly not today as we have guests):

[domen2003slo]

Marc,

i'll write down marks with specific number tomorrow when i'll go back from work (car will be well warmed up) - today i won't use car anymore -

thanks a lot for your efforts
Janko

[GiveMeABreak]

No worries. It may be the actual motor reduce unit itself - but you won't know whether the motor or the spindle until you get it out or into the area to test. Diagbox can test the actuators - but won't be able to check whether the spindle or gearing has snapped of course.

[domen2003slo]

Marc (and others) hi..

today i checked the temperature coming out from vents and all i can say is,that only from vent number 11 above the air is properly heated (all setting left and right were applied to HIGH)..there is also some not so cold air coming from vent number 12 (on the left side - right side is cold as hell) and 10. Every other opening (also at the back) is giving very cold air (AC on or off no matter)

any suggestions what to check ? Maybe matrix heater or something like that ? Flaps,motor,etc

tnx
Janko from Slovenia

[domen2003slo]

just update...today plastics were removed and all the flaps are ok - moving (thankfully) - motor is working ok,both hoses going to heater matrix are warm - so i and friend thought it might be Temperature sensor ? (when we rotate it a little bit,sometimes hot air is coming also from the right size,sometimes not..there is also other sensor on the matrix side - first one is this

http://www.easyautoparts.eu/en/sparepar ... 0100-denso

second one is this

https://www.ebay.co.uk/p/2014-CITROEN-G ... /646615541

worth checking ?

tnx

[domen2003slo]

update...heater matrix was changed and everything is ok...cost - 150EUR

[Slaay]

Hi. I have the same problem with my heating. Both sides are setting to HIGH, but the hot air blowing from the passenger side only. Driver side and rear blowing could. Anyone can suggest me some idea? Thanks

[GiveMeABreak]

This sounds like your air mixing motor control is faulty. If I understand you correctly, your fan speeds are working at all speeds low to high, but the heat is only coming from the left (passenger side), and cold at the right and rear?

Post your VIN up, so we can identify the correct mechanism for your C4 Picasso.

[Slaay]

Right. I took off the plastic cover and looked the flaps at all modes from high to low and they are working(moving)

[GiveMeABreak]

You misunderstand. Those are not what I'm talking about. There are (depending on options fitted) both air mixing and air distribution flaps that are for the most part electronically controlled by stepper motors and these are buried in the heating unit inside the dash, they are not on the fascia. That's why I need your VIN as there are different heating systems fitted, and that will tell me which system you have. I can't help you without this basic information.

[Slaay]

My vin
VF7**************[VIN obfuscated, can be read by forum staff]
Hopefully will help. Thanks

[GiveMeABreak]

Ok, so the motors I referred to are items (5) in the diagram.

The one on the right, and the lower one of the 2 on the left are for the air mixing function of the heater. These mix the hot and cold air.

[Slaay]

Thanks for diagram. I will have a look tomorrow if they have any signs of life.