MY CAR SOUND SYSTEM REQUESTING FOR CODE NUMBER.

It means that your car will want service in 25 days. I'm guessing you don't put a lot of miles on your car. The MB Assyst system will request a service every 365 days or 13,000 miles, whichever comes first.

Hello, Yes, many MB cars have security codes built into the stereo header units, including my own, (a theft deterant) You never really need to input it til you lose all battery power. If you have the orig. owners manuel it may still be in there. If not you may be able to get the code from the MB dealership using the vin number. Hope this helps a bit.
Regards,
Bill
1997 S500 owner.

Unlike p0 codes which are generic p1 codes are enhanced codes. p1999 is cooling system fan circuit which could be a number of things. Start with the obvious what in that system isn't working correctly.

MERCEDES-BENZ CAR STEREO CODES
https://www.carstereocode.com/unlock.php?mk=26

get the code from the dealer ,but you must be able to show you own the car.

Go to the dealer or call them, tell them this is my car and the radio has a code. I need to listen to the music and this car of yours is not letting me. They will give it to you or try reset it for you. Ask how much though before you do anything. They are expensive and they will not let you free easily without paying. No such free service especially from Mercedes.

Crank position sensors are known issues on the ML. It will not throw a code. It is plastic and cracks and when it faults car will stall.

Call a mercedes dealer and provide them with you VIN and the serial number on the back of your radio, they will give you the code.

to get the radio code you need to get the serial number from the back of your radio unit,,call your local dealer, give them the number and they will give you your radio code