Mercedes-Benz vehicles are renowned for their luxury and performance, but like all vehicles, they require regular maintenance to ensure peak condition. Understanding the Mercedes-Benz service codes displayed on your dashboard can initially feel like deciphering a secret language. Terms like “Service A,” “Service B,” and combinations like “A1” or “B5” might leave you scratching your head. This guide aims to clarify the Mercedes-Benz Assyst Plus service system, breaking down these codes and workshop indicators to help you understand your Mercedes maintenance needs.
Initially, Mercedes-Benz servicing was straightforward, primarily revolving around ‘A’ and ‘B’ services, often referred to as 1-spanner or 2-spanner services on older models before 2005. This system, known as Assyst, was designed to simplify maintenance schedules.
The original Assyst system featured two main service types:
- Service A (Minor Service): This typically included an engine oil and filter change, along with a basic vehicle inspection.
- Service B (Major Service): A more comprehensive service, Service B included an engine oil and filter change, pollen filter replacement, and a more detailed vehicle inspection.
Beyond these core services, ‘Additional service items’ were also necessary based on vehicle age or mileage. These encompassed crucial maintenance tasks such as:
- Air filter replacement
- Fuel filter replacement
- Brake fluid change
- Coolant change
- Spark plug replacement
- Gearbox oil and filter change
As Mercedes-Benz technology advanced, so did their service system. The introduction of Assyst Plus marked a significant upgrade. This enhanced system took into account not only time and mileage but also wear-specific maintenance items and any special equipment relevant to your vehicle’s specific configuration.
Assyst Plus first appeared in models like the 211 E-Class, 251 R-Class, 164 ML-Class, and 169 A-Class. One of the most noticeable changes was the expansion of service codes beyond just ‘A’ and ‘B’. The system now utilized letters up to ‘H’, potentially displaying Service A, B, C, D, E, F, G, or H.
This expanded letter system, while more precise, caused confusion for many Mercedes-Benz owners accustomed to the simpler A/B servicing. To address this, Mercedes-Benz refined the system further for models starting around 2008, such as the 204 C-Class and 212 E-Class. They introduced alphanumeric codes, adding numbers or letters after the initial ‘A’ or ‘B’ only when these ‘Additional service items’ became due. This resulted in codes like A1, B1, A5, B5, A3, AK, AC, B0, and more. This change coincided with the rollout of the Mercedes-Benz Digital Service Book (DSB), streamlining service record keeping.
These alphanumeric service codes are further linked to a ‘Workshop code,’ and each service task is assigned a number. To access the workshop code, you need to navigate to the workshop menu within your instrument cluster. On most Mercedes-Benz vehicles equipped with a 12-button steering wheel, this is typically done by:
- Turning the ignition to position 1.
- Ensuring the overall mileage is displayed.
- Pressing and holding the ‘call answer’ button, then pressing and holding the ‘OK’ button while still holding the ‘call answer’ button.
For example, a basic ‘A’ service is associated with the workshop code ‘505’. This code corresponds to service item 1 (minor inspection) and service item 3 (engine oil and filter change).
Another example, a ‘B1’ service has a workshop code of ‘E0E’. This translates to service item 2 (major inspection), service item 3 (engine oil and filter change), and service item 4 (brake fluid change).
From these examples, we can deduce the fundamental meaning of service items 1 and 2:
- Service item 1: Corresponds to an ‘A’ service (Minor Service).
- Service item 2: Corresponds to a ‘B’ service (Major Service).
- Service item 3: Engine oil and filter change – a standard component of every service.
The ‘additional service items’ you might encounter are:
- Service 4: Brake fluid change
- Service 5: Combination filter (additional filter on certain models)
- Service 8: Air filter replacement (sometimes differential oil, always check your service sheet)
- Service 10: Sunroof guide rails cleaning and re-greasing
- Service 11: Fuel filter replacement
- Service 12: Spark plug replacement
- Service 13: Engine coolant renewal
- Service 14: Main coolant circuit (potentially related to hybrid cooling systems)
- Service 15: Towing hitch lubrication
- Service 20: Gearbox oil and filter change
- Service 24: Cambelt replacement / Water pump replacement
It’s crucial to always cross-reference these service items with the specific service sheet for your Mercedes-Benz model. This sheet will contain detailed information relevant to your vehicle’s year, model, and engine. Service sheets can be accessed through Mercedes-Benz Workshop Information System (WIS) or platforms like Autodata. Here’s an example of a W212 E-Class Service Sheet Overview:
Service-Sheet-W212
Download
Initially, the variety of combinations seemed overwhelming. However, with experience and careful documentation, it became clear that the underlying service item logic is consistent across Mercedes-Benz models.
To simplify understanding, a compiled list of display codes, workshop codes, and corresponding service items is incredibly helpful. While still evolving, the following list provides a solid guide: (Note: This list is not exhaustive and may be updated.)
Mercedes-Benz Service Codes and Meanings:
| Display Code | Workshop Code | Service Items |
|---|---|---|
| A | 505 | 1, 3 |
| A1 | D0D | 1, 3, 4 |
| A2 | ||
| A3 | 550A | 1, 3, 8, 11 (Diesel) |
| A3 | 1, 3, 8, 12 (Petrol) | |
| A4 | D50J | 1, 3, 8, 10, 11 |
| A5 | ||
| A6 | DD0S | 1, 3, 4, 8, 10, 11 |
| A7 | G50M | 1, 3, 20 |
| A8 | Q50V | 1, 3, 10, 20 |
| A9 | GD0V | 1, 3, 4, 20 |
| A0 | 850D | 1, 3, 10 |
| AC | QD051 | 1, 3, 4, 10, 20 |
| AF | KD001 | 1, 3, 4, 8, 12, 20 |
| AH | 801050E | 1, 3, 13, 24 |
| AG | VD0A1 | 1, 3, 4, 8, 10, 11, 20 |
| AK | 10D0E | 1, 3, 13 |
| AP | 15D0K | |
| B | 606 | 2, 3 |
| B1 | E0E | 2, 3, 4 |
| B2 | 8E0N | 2, 3, 4, 10 |
| B3 | 560B | 2, 3, 8, 11 |
| B4 | B60H | 2, 3, 8, 10, 11 |
| B5 | 5E0K | 2, 3, 4, 8, 11 |
| B5 | 3E0H | 2, 3, 4, 8, 12 |
| B6 | DE0T | 2, 3, 4, 8, 10, 11 |
| B7 | G60N | 2, 3, 20 |
| B7 | GN061 | 2, 3, 15, 20 |
| B8 | Q60W | 2, 3, 10, 20 |
| B9 | GE0W | 2, 3, 4, 20 |
| B0 | 1607 | 2, 3, 8 |
| B0 | 960F | 2, 3, 8, 10 (GL63) |
| BD | M60T | 2, 3, 8, 11, 20 |
| BE | V6031 | 2, 3, 8, 10, 11, 20 |
| BF | ||
| BK | 10E0F | 2, 3, 4, 13 |
| BK | 14E0K | 2, 3, 4, 11, 13 (W246 Reader Submitted) |
| BS | 1Q60X | 2, 3, 10, 13, 20 |
Edit note: It appears that the number or letter following ‘A’ or ‘B’ indicates the same additional service items, regardless of whether it’s an ‘A’ or ‘B’ service as the base. Please contribute any missing codes or corrections via the contact link below!
To illustrate how to use this information in a real-world scenario, let’s consider my own Mercedes-Benz and its current service needs:
The standard service menu indicates that my car is due for a ‘BS’ service. Initially, this code alone isn’t very informative.
By accessing the workshop menu, I can retrieve more detailed information:
These displays reveal that the upcoming ‘BS’ service is due in 315 days or 13,600 miles. The workshop code is ‘1Q60X’, and the service items are 2, 3, 10, 13, and 20.
Breaking down these service items:
- B Service (Items 2 & 3): Major Inspection and Engine oil & filter change.
- Additional Items:
- Panoramic roof mechanism cleaned and re-greased (Item 10)
- Coolant renewed (Item 13)
- Gearbox oil/filter change (Item 20)
For an extra check, accessing the ‘Vehicle Data’ menu can also reveal details like AdBlue levels.
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The Curious Case of the ‘CH’ Service Code
Adding to the complexity, a Mercedes-Benz owner in Australia contacted me regarding a ‘CH’ service code appearing on their S212 instrument cluster. This was unexpected, as ‘C’ or ‘C-something’ service codes are not commonly documented for the 212 model series.
Despite initial skepticism, the owner provided a photograph confirming the ‘CH’ service display. The workshop code was ‘10405’, and the service items listed were 3 and 13.
Based on the service items, this ‘CH’ service included:
- Service item 3: Oil change
- Service item 13: Coolant change
Notably absent were service items 1 or 2 (A/B service inspections). This suggests that the ‘CH’ service might be a specific, regionally customized service interval or a system variation that omits the standard inspection components.
Attempts to find the workshop code ‘10405’ in WIS yielded no results. Given the vehicle’s location in Australia, it’s possible that service code variations exist in different markets. If anyone has information regarding ‘CH’ service codes or regional Mercedes-Benz service variations, please share your knowledge!
Understanding Mercedes-Benz maintenance codes is essential for proactive vehicle care. While this guide provides a comprehensive overview of the Assyst Plus system and common service codes, always consult your vehicle’s service booklet and a qualified Mercedes-Benz technician for accurate and model-specific maintenance advice. Regular servicing, guided by these codes, will help ensure your Mercedes-Benz continues to deliver the performance and reliability you expect.
