2009 S550, 75K miles

Having problems with draining of the starter battery.

SDS fault code check revealed an issue in the driver-side SAM...

Code: 9233

Status: Stored and Current

Description: One or more wires to component "F32K2 (Quiescent current cut-off relay)" is faulty.

Is this a valid code?

Inspection of the wires connecting to the relay box reveals all are corrosion free, large gauge and connected firmly to the relay box.

The relay box is numbered 221 540 26 50. Does this relay have a history of reliability issues.

If the wires externally appear in good condition, should they then be traced back to the respective components they supply?

Or should each be inspected with a clamp meter for active current draw?

SDS provides an active test for the SAM - Quiescent current shutoff

When tested, the F32K2 relay passed, dropping current to zero volts.

Any insight to this issue?

Removed the quiescent current cutoff relay from the engine compartment and disassembled it. Unit has five large and medium diameter wires connected to it on the top side, including a line from the (+) battery post, and two plug-in connectors on the reverse side. Disassembly was uncomplicated and easily performed.

Even though the relay had a protective cover plate, found that some water had entered, resulting in a mild amount of corrosion on some leads, connection posts and the conductor plate.

Using a Dremel with a small brass wire brush, cleaned corrosion from all components; reassembled, reinstalled and ran fault code check for the front door SAM that initially reported the fault. No further fault codes were found and vehicle has remained trouble-free.