SL350 2003 won't start, Keyless go wont open car or turn in ignition but then might work a couple of hours later.

[fynn2003]

I have replaced the auxiliary battery as the fault was draining that. The key (and i have tried both) wont open the car or turn in the ignition, When you get in the mileage displays on the dash and interior lights worked but nothing else. Then a couple of hours later it all worked fine. But now it has failed completely.
Is there a relay or something that could have failed?

 

[Dickster]

I had similar happen to mine. Key wouldn’t turn in the ignition. It might be the key or the ignition switch. I would get a mobile key guy out to look at it. Mine was fixed with two new keys.