willy_manilly

Well my car had the standard climate unit with the two knobs (without LCD)

So a few weeks ago i changed up to the unit with LCD and everything was working fine.

Last week i changed my bumpers to the AMG model. Ever since i did that, i can't get any hot air from my climate control.

Even if i put it up to HI or 30 i get nothing.

Does anybody know what could have caused this, there was a front TEMP sensor behind the bumper which i had to relocate to another position to fit the new bumper, but i don't think that would affect anything?


Cheers

johnng117

I'm also having this problem too, no errors when plugged into STAR.

willy_manilly

I think ill swap back the hold heater controls and see if that makes a difference, if not ill check temp sensor. If that doesn't work ill have to take it to the dealer

ozusa

https://mbworld.org/forums/e-class-w...rol-valve.html

A valve that doesn't open is at the heart of the symptoms you are experiencing, the question is whether it is being "asked" to open and not cooperating, or is not even being asked.

Since one of you is from Melbourne (and it's February), and the other from Hong Kong where it is hardly arctic, even in February, replacing the heater control valve may not be the fix, but it is worth understanding that possibility and the repair. If you happen to be running your cars with plain old water and not MB antifreeze, as people in warmer climates can get away with, you may have a build up of minerals that is making the control valve's open/close job harder.

I find that the one in my car could do with replacement, since it is a bit slow to open in below-freezing conditions.

Milly, I know you said you recently changed the controls, so I wonder if the wiring is such that the heater control valve is not even getting a signal to open/close. (I am probably wrong on this, and I am not sure how you'd test it. I think I have heard of others doing this change and it works to provide basic heating. )

So, if after swapping back to the standard heater control, you are still without heat, consider replacing the valve.

All that said, if your temp sensor is bad, this isn't going to work.

willy_manilly

UPDATE:

I checked the engine coolant today and it was down a fair amount.

After i topped it up to full the heater is working correctly again, and i now get cold and warm air.

So im guessing when the coolants low the heater can't get enough coolant from the tank and then fails to operate.

ap10046

Mine Doesn't really work either.
Any quick n' dirty way around this, without stripping half the firewall?

ozusa

The objective of the following is to attempt to get the electronic controller to "try again" to open the valve.

1) Turn the system off and back on (restarting the engine will probably have the same effect). That may cause the controller for the valve to recycle and send another signal to open it. Perhaps the valve will respond, perhaps not
2) If the ambient air temp is very low (below freezing), consider moving the car to a warm garage and powering the system on and off. This assumes that the valve's response is better when warm
3) Wait for the engine to reach operating temperature and power aircon on and off until you get a result from the heat valve. Again, this assumes that the valve's response is better when warm

The above has worked for me twice this Winter, but come the Spring I will be replacing the valve.