W212 - Thermotronic (Climate Control) buttons won't work when pressed down

[matt_1]

As per title. The function of the bottom row of buttons will only work when pressed up; the downward function won't work.

Looking at this picture, it is buttons 9-12. They will all raise the temperature, raise the fan speed, or change mode upwards, but they won't work when pressed down.

No obvious signs of anything blocking them from below.

Has anyone had this issue? Any suggestions?

Thanks!

 

[matt_1]

W212 E-Class, 61plate

 

[mattkh]

..... but they won't work when pressed down.
Thanks!

Do you get a feel that a button is actually going down or not...?

 

[matt_1]

Update - the whole unit seems faulty now; it won't even turn on now.

I am just trying to get it booked into a Mercedes specialist nearby.

 

[matt_1]

Update - mechanic says the unit is faulty. What are the chances it could be a loose connection, not a faulty unit?

I might try and install a new unit myself. It looks pretty simple, according to this video.

Are there things to avoid / things to make sure I do if I attempt this? Disconnect the battery before I start?

 

[matt_1]

A quick update for future forum users who may have the same issues.

• Climate Control Unite (the one in the video above) died a slow death on my W212.
• First the row of buttons would only work pressed upwards, then a few days later, the whole unit died.
• After it died, the check engine light came on.
• After that, when I was driving, the engine fan would blow full blast.

Unsure why or how the engine fan and climate control are linked, but they are it seems. I changed the unit for a second-hand one off eBay, £35. I made sure all the serial numbers on the back matched the ones on the ebay one. It was from a coupe, mine's a saloon, so the outer casing was different, but a few screws and you can get the PCB out of the unit and put it in your existing unit. Helps if the one you are buying is a scratched-up mess as well.

After that, the unit turned on, the heaters blow, and the fan on the engine stopped blowing. The engine light stayed on, but I have just driven it a few hours later and the light has gone off.

A word of warning though – be careful putting the screws back in the dash. I dropped one, no idea where it's gone behind the dashboard. I hope it doesn't get in the way of anything or rattle around.

 

[brandwooddixon]

Unsure why or how the engine fan and climate control are linked, but they are it seems.

Common for the main electric fan to be used to cool the condensor for the air conditioning, perhaps that was what it was doing.