So awhile back, my cabin dimmer, the one next to the headlight switch, stopped working. It doesn't dim anything anymore (dash, radio, door etc). I've recently discovered that the dimmer corresponds with something called terminal 58. Does anyone have more info on exactly what that is or does? In live data, it says terminal 58 is at 100% and the dimmer doesn't change that value. I'm beginning to wonder if it's a fluke hardware failure...
Bäsemödel: Hi - The answer to your question lies in part with
DIN 72552 (DIN is short for Deutsches Institut für Normung, or in English "German institute for standardization").
So, this standard applies to automobiles and it abbreviates into numbers, the various electrical functions. For example. Terminal 30 (or T30) is a solid 12 Volt supply, T15 (i.e. half T30) is a switched 12 V supply and T31 is earth.
As for your specific question, T58 is the lights for licence plate and instrument panel. However, I suspect that you meant to say that the "cabin dimmer" was
Terminal 58d because this is the specific nomenclature that DIN 7552 gives to the instrument panel dimmer.
You can find the full listing of all "T" numbers
HERE
As for your problem, you might take a look at the value for Byte 7, Bit 0-1. This grouping of Bits controls the function that OBD11 calls "Lighting adjustment_Input media" (this is my translation for the original German- probably not correct), see the screenshot below:
This entry has the following 3 x allowable values:
not installed=hex0
Potentiometer=hex1
Button=hex2
HMI=hex3
The screenshot show the setting "HMI" which means that a "virtual" electronic slider appears in our RoW cars on the MENU to control the lighting level (we don't have a physical dimmer on our cars). I assume that the correct value on NAR vehicles is "Potentiometer".
Might be worth checking your car IMO
Don