SuzyQ

Drive the car and it's fine, park car overnight then in the morning the door locks won't work and have to manually unlock and can't won't turnover. Nothing - complete silence. No lights, no click nothing. Have to get a jump, but it takes a while to turn it over. Mercedes service can't find the problem - nothing shows up for codes. Charger system checked out fine, battery has been replaced 3 times, starter and alternator fine as well. Any ideas? It acts like the theft system shuts the car down. Mercedes had the car for 3 weeks and of course, the problem didn't happen for them and it always started right up. It doesn't matter how long the car sits - it will happen when you least expect it. Since Mercedes couldn't find a problem, they changed a few relays and that seemed to do the trick, but now the problem is happening again. Mercedes didn't write down what relays they changed and have no clue what they did. Not sure if this has anything to do with it, but it seems to happen when the weather gets a little cooler. HELP

SanMan

I dont know if this would do any good, but you can try using spare keys. Also may be you can have your dealer think in those lines and get a new key. If it has to do with engine immobilizer, may be they keys are relaying bad code intermittently. Hope this helps

angeleye328i

Bad battery, just replace it and everything should be good..

blurooster

She mentioned 3 new batteries...

Has anything been replaced or added? Radio, video equipment?