After buying a '94 S500 Cpe and running it for about 2 years, the CEL came on. Car ran fine but after reading codes (DTCs), it 'pointed' to the DI Module (Menu#5).

At that time a new ECU was $1700, so decided to 'learn' about MBs and fix it myself. That was the start of what is now my "My S500 Cpe" web pages.

The DTCs from the DI Module; PN 015 545 61 32:
Active--------- CKP Sensor Defective (L5)
Registered------ N/F
Stored--------- N/F
N/F = No Faults

It appeared as an "active" fault and that turned the CEL on. Since it was an active fault, it wouldn't erase. It appears that the Diag memory in the DI Module that stores 'faults' went bad similar to a bad memory element in your computer's SD-RAM. It fault pointed to a "CKP-sensor" which wasn't really bad!
Unfortunately, the only way to fix it was to replace it.

Found a replacement for $225 in a NYC junk yard and that fixed the problem and still going strong today.

Check out my various sections for other info.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page