After the unsuccessful attempt in repairing the K40 module assembly I decided to replace the complete assembly. Even though the solder connections were solid the actual relays may be defective when in use. I located a used module from a donor 1999 SLK230 that had gotten into a front end wreck. I removed the original and installed the replacement module. I also went ahead and soldered the known area of solder connection problems.

The car has been running strong for approximately 700 miles with no CEL activation. I can conclude the 2nd K40 module is working properly.