For a 1.8-litre C180, C200 or C250 CGI W204/S204, plan the service from the exact engine, the full ASSYST PLUS message and the renewal history. The useful distinction is between work due under the vehicle’s service requirements, work already recorded, and faults needing separate diagnosis.
Coverage: early 1,796 cc petrol C180, C200 and C250 CGI BlueEFFICIENCY in the W204 saloon and S204 estate. This guide excludes the Kompressor engines, later 1.6-litre M274 C180, CDI diesels and V6 models. Check engine identity before applying a specification.
CGI, Kompressor or the later C180?
| Early CGI application | MANN engine entry | Output |
|---|---|---|
| C180 1.8 CGI; 204.049/249 | M271.820; 1,796 cc | 115 kW / 156 hp |
| C200 CGI; 204.048/248 | M271.820/860; 1,796 cc | 135 kW / 184 hp |
| C250 CGI; 204 series | M271.860; 1,796 cc | 150 kW / 204 hp |
These are manufacturer catalogue applications, not a promise that every car registered in a particular year has that engine. MANN separately lists the later 1,595 cc M274.910 C180 and the earlier Kompressor variants. A “C180 BlueEFFICIENCY” description can therefore be insufficient for ordering parts.
If your car is a Kompressor, use our W204/S204 Kompressor maintenance guide. A shared M271 family name does not make its filter references or oil table interchangeable with the CGI entries.
What does the service message actually mean?
The inspected 2011 Mercedes manual describes A as a minor service and B as a major service. A following number or letter indicates additional maintenance. It directs owners to the separate Service Booklet for service types and intervals.
Give the workshop the whole message, not just “B service”. Ask it to identify any extra operations for your car and explain why they are due. The W204 ASSYST PLUS code guide provides the display context; a suffix such as B5 should not become a fixed internet parts list.
Turn a used-car history into a maintenance plan
Start with invoices rather than a package name such as “full service”. Record what was actually renewed, its date and mileage. Mark a missing entry as unknown so a garage can distinguish an inspection, a scheduled renewal and proposed catch-up work.
| Item | Record worth retaining |
|---|---|
| Engine oil and filter | Oil product, MB approval and complete fitted filter reference. |
| Air and cabin filters | Separate renewal dates; cabin-filter steering-side application. |
| Spark plugs | Exact reference, quantity and previous renewal date/mileage. |
| Brake fluid | Renewal entry, distinct from a fluid-level check. |
| Transmission | Gearbox identity and separate evidence of any applicable fluid/filter service. |
That record makes quotations easier to compare. If one quote includes plugs while another only includes oil and inspections, first establish whether they cover the same work. Ask for labour, parts and VAT to be clear before comparing the totals.
Oil, filters and plugs: useful checks before a booking
The inspected manual lists the early non-Kompressor C180/C200/C250 BlueEFFICIENCY petrol entries separately from its country-specific C180 Kompressor entry. Our CGI engine-oil guide explains that table and the nominal 5.5-litre oil-and-filter quantity.
The CGI filters and spark-plugs guide checks the engine air filter, complete oil-filter references and a right-hand-drive cabin option. It also distinguishes the supported C180/C250 plug entries from a C200 CGI application that still needs individual confirmation.
A correct part reference is not a replacement interval. Use the requirements applying to the car and its previous renewal dates to decide when a part is due. Do not buy a kit simply because every item in it is advertised as compatible.
Stored cars and service resets
Mercedes says ASSYST PLUS does not count periods with the battery disconnected. Tell the workshop if the car has been stored that way, including the dates. The remaining display cannot by itself establish the elapsed calendar time.
Have the reminder reset after completed servicing and retain the invoice. Resetting a display does not document the oil used or establish that additional operations were performed.
Keep fault diagnosis separate
A rough-running engine, unusual noise or warning lamp deserves a clear fault description. Replacing routine plugs and filters is not proof that those parts caused it. Ask for diagnosis and any proposed repair to be separated from the scheduled service quotation.
For gearbox work, supply the transmission identity rather than assuming a fluid requirement from the C200 or C250 badge. The same principle applies when choosing scanner coverage: match the systems you need to inspect.
Explore the Mercedes maintenance hub and the Mercedes diagnostic scanner guides for separate fault-finding questions.
Sources and applicability
- Mercedes 2011 C-Class manual, printed page 326 / PDF page 329: ASSYST PLUS and service information.
- MANN current C 3210 applications and MANN 2024–26 catalogue, printed page 207: early CGI, Kompressor and later C180 distinctions.
Checked 20 October 2026. The inspected Mercedes-hosted 2011 manual covers saloon and estate. Its online disclaimer specifies German-market coverage and says it does not replace the manual supplied with the vehicle. UK owners should match their own manual, Service Booklet and supplements.
