C4 Picasso 2017 Hot Air Only on Driver Side

[chrisnasulea]

Thanks, everyone,

The problem is that the thing that's broken isn't part of component 14 in the diagram. It's the pesky little plastic end that comes out of the main heating unit and clicks into the lower part of component 14.

Or, rather, to describe it better, it's component 14 that clicks onto this little rotary plastic piece sticking out of the main heating unit. So, everything in the list of parts that belong to the Air Conditioning Control Kit, part number: 9821297680 is intact. The thing it's supposed to hook up to is broken.

It seems crazy to replace the entire main heating unit over something like this but I don't think the broken bit is available separately. Is it?

Chris

[GiveMeABreak]

No, it doesn't look like it. I can see now (I've placed your images now into the post) where the part that has broken off and it does look like it's on the main heating unit which is a complete unit....

Are you going to replace the whole thing? It's a hug job to get this out, draining the cooling circuit and the A/C system with a vacuum machine, dash trims, steering column, storage compartments, centre console, telematics...

[myglaren]

Similar system on the C3. Had my daughter's done last year, lots of new bits and a new heater matrix, works very well and wasn't terribly expensive as the cost includes a service, MOT and tyres.

[chrisnasulea]

No, it doesn't look like it. I can see now (I've placed your images now into the post) where the part that has broken off and it does look like it's on the main heating unit which is a complete unit....

Are you going to replace the whole thing? It's a hug job to get this out, draining the cooling circuit and the A/C system with a vacuum machine, dash trims, steering column, storage compartments, centre console, telematics...

I need to gather a bit more information before I decide which way to go with this. I'll first ask a few places for a quotation on the replacement of the heating unit.
I'm also considering bridging the broken part by inserting a hot thin strip of metal through the two pieces of plastic to reattach the broken tip to the heating unit.
All of this also depends on whether or not we will succeed to get the unit to be "stuck" in the hot position instead of cold. If we do succeed with this operation then fixing the whole system will be less urgent.

[GiveMeABreak]

I suspect you won't be able to do that without breaking something else! As I said, there are both air distribution and air mixing flap motors. If you try and stick something permanently in place then you will destroy the motors and or the other flap gearing, due to the climate control automatically attempting to adjust the temperature and the distribution. And further, this system will occasionally operate the flap controls independently as it calibrates the system, This is usually done after the battery has been disconnected. So regardless of what setting or temperature you aim to keep it fixed at electronically, it won't work mechanically or electronically if you try to work against the motors.

Labour times alone are about 6-7 hours to replace the assembly as there are so many components and trim to be removed to get at it, plus the cost of the new unit itself if it can't be repaired.

First - can you be absolutely 100% certain that the black part that has broken off is not actually part of the replacement kit? Given that the black plastic part remaining inside the white plastic housing is the same colour as the control arm replacement 'kit', I personally think that it is part of the control arm mechanism and that it just plugs into the socket on the white housing and has sheared off here. I can't see them making a kit that can break off like that which requires the whole heating unit to be replaced!

I think it may be better to check the replacement kit part out first and see if you can confirm whether it looks like it plugs into the area where the remaining black plastic part has torn off - leaving part of it in the plug. If that is the case, it may simply be a matter of pulling out the black plastic part that is stuck in the side and replacing the control arm with the kit.

[chrisnasulea]

Update after 10 months.

The AC still isn't fixed. Lack of hot air on passenger side simply wasn't a priority during the summer months. The return of the cold weather rekindled my interest for the issue so I'll probably take it into a dealership to have the matrix replaced.

I just wanted to mention something else that might be helpful to others. The lack of error codes on the various diagnostic tools was due to a problem with the OBD port. So, the car's brain was detecting problems with the AC, it just couldn't talk to Diagbox.

[Nobodzy]

Interesting, i have the same Problem since 2-3 weeks.
Opened every thing up today but All seems fine and working there, and you can See the lids open and closing too. But somehow no Hot Air for the passengers side. What els reason could there be that gives me the same Problem?

[johnsm13]

@chrisnasulea Would be really interested to hear if/how you resolved this as we have exactly the same problem on our C4 Grand Picasso. Was it a very expensive dealer fix, if you got it sorted?
Thank you
Mike

[RichardW]

Most likely it needs a new heater matrix. Parts are not dear, and it's not hard to fit, but I'd avoid the dealer!!

[C4 mk2]

It's a heater matrix. I checked other poste, guy replaced heater matrix and have no problem after that. If aster diagnostic doesn't show any error on motors try heater matrix. It's tricky to replace but not that expensive.
Best of luck

[Aaad4m]

Hi there Sir.

I own a 2016 Citroen Grand C4 Picasso 1.6 HDi UK model.

I have the exact same issue as you with that black plastic bit broken off. Exact same issue as you.

Did you manage to fix it and if so how.

I can purchase the part 9821297680 but unsure how to remove the plastic bit that stuck inside the motor flap.

Any help would be appreciated as its doing my head in right right.

Am getting hot air on passenger side only and driver side blowing cold air.

Thank you.