MCS no longer taking security code: 2000 ML320
 

i recently replaced my battery on my 2000 ML320 and of course the radio asked for the security code. The code that i had been using since i bought the car no longer works. I pull the radio out and get the serial number and contact the dealer and they give me an alternate code to work. Still no luck, I reset the radio about 4 times now and still both codes do not work. Any ideas what this could be? I read on another forum that the MCS may need replacement and a used replacement is around $500 from my resources. If this is the case, i may just get an aftermarket replacement like a Kenwood avh-p4300DVD which goes for around the same price. Thanks folks

After the third attempt to enter the code the MCS goes into a WAIT mode. Depending on the number of attempts you may have to WAIT up to 24 hours depending on model of Mercedes. I think the ML only require a half hour to one hour wait. It's important to know that the MCS must be turned on during this wait period. If the MS screen says WAIT you may want to leave the MCS on with a battery charger on the battery for the WAIT time to elapse.
Mike

thanks mike. yea, i am familiar with reseting the mcs when it goes into lock out mode. i have done it maybe 4 or 5 times already. i usually just leave it in the second position for about an hour then it lets me re-enter the code. what my issue is, is that my code that i used to use as well as another code the dealer gave me based on my serial number on the mcs doesnt work anymore. has this happened to anyone?

Hello...I have a 2000ML320 and I'm experiencing the same issue as yours, the security code I used to enter whenever I disconnect the battery no longer works...where you able to resolve this problem?

still no resolution. I havent had a radio for a while now. The only thing i can think of is replacing the unit with an aftermarket double din. :smash: