Ask the owner or review service history: Was the ECU, EIS, or TCU changed in the last 6 months? If yes, the used module is almost certainly the culprit.
Workshop Code 606 translates to "The coding of the control unit is incorrect or incomplete."
Use the scanner’s freeze frame data for Code 606. Look for "system voltage" at the time of storing. Values below 11.0V indicate a brown-out during coding. Mercedes Workshop Code 606
A technician performed a flash update via Star Diagnosis (DAS/Xentry), but the process was interrupted (low battery, cable disconnect, or network error). The unit now has partial programming—hence "incorrect or incomplete coding."
This is for experts. Incorrect values can brick the ECU. Ask the owner or review service history: Was
In the lexicon of Mercedes-Benz Star Diagnosis (SDS) and OBD-II scanners tailored for European vehicles, is not a traditional "check engine" fault code like P0300 (misfire) or P0171 (lean mixture). Instead, it falls into a category known as *"development codes," * "workshop codes," or "manufacturer-specific informational codes."
A comprehensive technical inspection of the vehicle, including the braking system and tires. Service Item 3: A standard engine oil and filter change. How to Find the Code in Your Car Look for "system voltage" at the time of storing
Some owners report that Code 606 clears after an "adaptive reset" – disconnecting both battery terminals, touching them together (away from the battery) for 10 minutes, then reconnecting. This forces the modules to re-initialize and re-learn variant codes. Success rate: ~15%. Free to try.
Workshop Code 606 is not universal. It is most prevalent in the —the M112, M113, and OM642 engine families. In particular, vehicles equipped with ME2.8, ME2.7, ME9.7, or CDI3 engine management systems report this fault with higher frequency.
🔁 Usually means: Brake fluid flush, coolant, or other calendar-driven maintenance.
According to technical service guides from James Cooke Automotive , Workshop Code 606 typically triggers a interval. Specifically, it calls for: