ML320 Remove Key & Column Lock Doesn't Occur

[slnole]

Sorry if this has been addressed previously... I've looked back over several months of threads, but haven't found one that addresses this problem...

A couple of days ago I noticed that when I removed my key from the ignition, the familiar "click" was suddenly absent... The warning 'beep' that you hear if you have left your key in the ignition, and open the door, continues & the remote lock/unlock doesn't work... I thought it might have something to do with the batteries in the remote needing to be replaced, but found out this evening that it must be something a bit more involved, after I replaced the batteries with no impact on the problem...

Any insights/suggestions would be greatly appreciated !

SLN

98 ML320