Neither remote would work on my shiny new (to me) 2001 SLK320. The door lock/unlock would work on console with engine running.
1)Ok, tested batteries in remotes (hold down lock/unlock buttons at same time, will blink if battery ok) batteries ok
2)Sync remotes ( briefly press lock or unlock twice, then within 30 seconds turn ignition to position 2) Remotes synchronized, lights blink when lock or unlock is pressed but doors, trunk, etc do not lock- Semi-Fail
3) Decided to come to the source=SLK World. Ok most likely PSE with barnacles or Fuse 9 or both.
4) Path of least resistance=Fuse 9- yes, it was blown. Did not have 10 amp, but since Volvo is kind enough to put spares in the fuse box, I walked over and got one-Everything now works!
5) Now have plenty of fuses after a trip to Advance.
6) Next step, wait and see. Then troubleshoot down the line if it blows again.
I am going to take a peek at the PSE regardless when the weather warms up a little in the next few weeks.
Thanks for all the threads and postings on this issue