Some people know that your A/C display yields a wealth of information via a hidded DIAGNOSTIC mode.

Here is a picture of what the A/C in diag mode looks like. This particular mode shows engine rpm.

A/C Diag Mode.

To get into the Diag mode, with your engine running hold down the REST button for 5 seconds. Once in Diag. mode you can toggle through the various registers by pressing 'air up' and 'air down' .

Cycling digits will show you reg number/value. To exit Diag. mode, hit the REST button again.

Now their meaning (from the ones I know):

1 in-car temp
2 temp outside
3 heater core temp, left
4 heater core temp, right
5 evaporator core temp
6 engine coolant temp
7 refrigerant pressure (in bars)
8 refrigerant temp
9 not used
10 blower control voltage in range .8 - 6V (max)
11 air pollution sensor
12 sun sensor
20 control current of aux fan
21 engine RPM (x 100)
22 vehicle speed, km/h
23 terminal 58d battery charge, percent
24 battery voltage
40 software status register
41 hardware status register

Does the CLK 430 work with this?

Yes.

I have a 2002 CLK 430, it seems to work the same way, I don't think that the specific items are the same, does anyone happen to know the specifics for the older climate control system ?

what about the c coupe that doesn't even have that screen?

I have a question about what some of these things are:

What is the Heater Core?
What is the Evaporator Core?
Refrigirant pressurE?
Blower control?
Aux. Fan? (What does it do?)
Terminal 58d Battery?
And Software/hardware status register?

Thank you for your help on making me understand these more.
Regards,
KU104

Anyone????




BTW I tried the thing in the 99 S320 it didn't work however it did work in the 00 E240 is it something related to model yeaR??

Bump for users that have been asking.

So this just displays what the settings are at right? how come when I was playing with this menu, the heater now blows only cool air? I'm gonna bring my car in to the dealership but it's been getting colder here.

That is correct. This is a static display of variables only. You can not change/update anything via this menu.

after getting into this menu, it seemed as though the temps were a lil off. the higher temps (75-83) wouldnt be as warm as they used to be. but i'd have to turn it up to 86- HI. i tried to do a system reset on the COMAND but I don't know if that does anything.. please shed some light on this. thanks

This won't work with dual-zone A/C without LCD screen...