Parktronic - strange problem

[DukeThrust]

Hi guys,

My W121 E63 5.5 has developed an odd and occasional Parktronic problem:

When you first start the car and put it in gear the front sensors beep and then the two inner amber lights come on, on both sides (four in total), but not the red ones that when researching the problem seem to be more frequent.

If you switch the car off and then back on again, the problem goes away. It's only occasional and seems to be (so far) only at the first start up in the morning.

Any thoughts?

Thanks!

 

[DukeThrust]

Found the problem, it was not getting enough power when starting: If I paused for a second or two after turning the key to position 2 (just before engaging the starter) it'd work perfectly. Presumably it does some sort of pre-check.

Changed the battery and all is functioning perfectly again.

 

[Blobsta]

Another one for the "Mercedes bizarre behaviour with low voltage" pile then. Excellent and thanks for posting the solution.