Powerplay

Hi guys! I am a new member of this board and so far you guys have been awesome! You guys know more than my MB Dealer!! (ie. the bluetooth "Puck with tail" - Thanks for the help with this one!)

Ok - here is my question....

I have a 2004 E500 4Matic. The climate control seems to be off? When I set the temp to 70F - it heats the cabin to about 90F! Additionally, my rear heating control DOES NOT function at all - no display, no controls. Lastly, my outside temperature on my dash reads 185F?? (I live in New England - I don't think it has ever been 185F )

Are all these things inter-related?

Has anyone had similiar issues - fixes??

Thank you guys in advance for any advice!

KJ

amdeutsch

Not sure on your interior issue, but your outside one is easy. The sensor has dislodged and is now reading engine bay temps instead of outside temp.

Diesel Benz

You would have read fault codes from the car, those should indicate the issues with the AC. Or then test AC in test mode. Even your dealer should be able read the codes.

How is it with your rear AC by the way, can you control the settings from the front?

I guess the exterior temp sensor could be even completely detached, like a cut wire. Does it show the high temp reading already after switching on, before the engine is warm?

Barry45RPM

When my outside temp sensor got damaged and was disconnected from the wire, the display read 185. That must be the number it displays when it is out of the circuit.

Your interior issues need to be checked by the dealer.

Powerplay

I'll take a look at the exterior sensor tomorrow. I located it in the front lower grill, it looked in tact, but maybe it's disconnected or cut in the back??

As far as the rear temp control...I CAN change the temp from the front controls - but no controls at all from the back. Does anyone know if there is a fuse dedicated to the rear climate control? I looked at the fuse box in the drivers compartment and nothing there...I don't see a schematic (sp) for the fuse boxes in the trunk or under the hood???

Powerplay

Well guys - I fixed the $23.00 piece of plastic which was the exterior ambient temperature sender and now my climate control works like it should. It had a hairline crack in the sender and it caused it to short circuit and confuse the system. Go figure??

My rear AC/Heat still does not work however?? I checked the fuses - nothing blown? I don't have a reading or anything back there. I can control the rear heat/AC from the front controls - but not from the back controls? There isn't even a display on the screen? Does anyone have any thoughts on what might be wrong back there??

ohlord

you check all the fuses?There is more then one fuse box.
Did all the systems go when the outside temp sensor went bad?It may have tripped the system if it did go out at the same time.Sometimes a simple reset of the battery will reset the system glitch.
W210 have the onboard diagnostics so maybe see if it runs on your 211 or ask around how to get it on your model
http://www.eclassbenz.com/node/27
good luck

Diesel Benz

The W211 AC unit has a similar diagnosis mode even if the device looks very different (this is on the 4-zone car).

However I doubt this would be connected with the temp sensor issue, I'm guessing more like a wiring or connector issue, or a malfunction at the rear unit. The rear display/control unit is really simple, only a single active wire to the front unit, plus ground, power and illumination.

Powerplay

I agree, it seems to be something in the climate control box in the back seat. Does anyone know how to remove that panel??

konigstiger

It may be a combination of the driver’s side SAM (signal acquisition module) malfunctioning and possibly replacement of the heat exchanger valve. Mention DTB P-B-83.20/72 SEPT04 and they will check for DTCs (diagnostic trouble codes) and perform an actuations test under warranty.