N22 Read-Out Values
Via (Climate) Control Module

1. In-car termperature sensor (with aspirator blower)
2. Outside temperature sensor
3. Heater core temperature sensor
5. Evaporator temperature sensor
6. ECT sensor (Coolant temp.), e.g. 12*5 = 125C
7. Refrigerant pressure in bar, e.g. 12*8 = 12.8 bar
8. Blower control voltage, e.g. 16*5 = 1.65 volts
9. Software status of A/C pushbutton control module
15. Selected in-car temperature
20. Version code
21. Engine Speed (RPM), e.g. 6*0 = 600 rpm
22. Terminal 58d (Bat. Volt.), e.g. 99.0 = 99% of voltage
23. Vehicle speed (Kilometers Per Hour)
50. Not used – 00
51. Number of current slip recognition (poly-V-belt)
52. Number of stored slip recognitions (poly-V-belt)

This code system works for my 95 C280 (produced 10-94), it's not supposed to work for models earlier than 95, but give it a try anyway.

This is what I typed and laminated so I will have a "quick reference" card in my car!! HAHA :) This was kind of a mix between 2 different version codings, but it works exactly for my car. I have 2 lists, so if you want any other codes, or some are wrong on yours, just let me know and I'll look them up to see if I can help you. Again, thank STEVE for all this!!!


[Edited by Hottee18m on 02-20-2001 at 03:56 AM]

Post'em Please
 

David,

I would like to see the codes if you don't mind posting them. I have the same car as Chris so it would be interesting to see what information is available.
Thanks, :)

Scotty Bates

Questions!
 

Now that I know what codes corresponds to what, I need to know what they mean!!

1 What is the Heater Core??

2 The evaporator core temp is what?
3 ECT sensor is coolant sensor? And is it in Farenheit for US models?
4 Refrigerant pressure... I won't worry about that one.
5 Software status of AC? Not a variable?
6 Version coding?? not a variable either?
7 What exactly is 22? the Battery volt? 99% of...? I do'nt understand?
8 And is the poly-V-belt the fanbelt? Is this helpful for telling me when I might need a new one? or have a problem with it?

Thanks to anyone who can help.

Heater core- Mini radiator that heats the air for your heater, air runs through it when it is filled with hot coolant
Evaporator- Contains aircon refirgerant, air runs through it too cool your car
Coolant temp- Ferenheit in 97 C280
Refrigerant pressure- Pressure of refrigerant in A/C system
Poly-V belt- Drives all the accessories, A/C compressor, coolant pump, power steerin pump etc.
Battery voltage- voltage of the battery, self-explanatory?

Thanks Ali, you're the best.
But about the batt voltage... that would be 99% of 12 volts? or what? thanks

That's what I interpreted it to mean.
However, a fully charged battery is 12.6 volts, so maybe it is percentage of 12.6 volts

We are currently trying to place an A/C article that I wrote last June to this site. It will do a better job explaining belt slip.

Basically the compressor control system looks for belt slip by monitoring the speed of the compressor (speed sensor in rear head) versus the speed of the motor. The point to all this was to anticipate a compressor that was locking up. If such a thing were to occur the belt would be destroyed and all the other accessories would quit turning; especially the water pump (not such a good thing).

The computor software verion is only important for reprogramming.

The variant code is capable of being changed at the head and can be very important. It is the way that one can change from temp in Degrees C to degrees F. The improper coding of a gas motor as a diesel will keep the compressor from coming on. This is one of the cautions mentioned somewhere in this thread.

Steve, I look forwarding to reading that article!
Also, how do I change from C to F? And let me know what NOT to do to switch it to a diesel!