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Coupe/Convertible Forums Moderator
CURRENT: 2011 SL550 FORMER: C300, ML350, CLK550 Cabriolet, C240, ML320, 300TD
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Discussion Starter · #1 · (Edited)
MBZ Mercedes-Benz – Also abbreviated as “MB”. Mercedes-Benz AG, a subsidiary of Daimler AG, is a company that manufactures and sells Mercedes-Benz branded vehicles. There are some sub-brands of Mercedes-Benz such as AMG, Maybach, and EQ, and Smart. Daimler also has other subsidiaries that manufacture trucks and buses. Mercedes-Benz, MB or MBZ is typically used to refer to the Mercedes-Benz branded passenger vehicles.

SDS - Star Diagnostic System – Also referred to SD, Star, DAS or Xentry, this is MBZ's official diagnostic computer system designed for dealers and high-end shops. It's Windows-based software that includes DAS/Xentry, WIS, EPC, and other useful tools. SDS is versioned by the month and date of its release, such as "10/2008" for the October 2008 version. Generally, you must use a version of SDS that includes your car's model year, so a 10/2008 version may not work on a MY2011 car.

DAS - Diagnostic Assistance System - the software tool within SDS that communicates with your car's electronics to read and clear codes and change settings. Don't confuse this acronym with two other MBZ systems: Drive Authorization System, the electronic process used by the car's electronic ignition switch to validate the keys and the new Dual-Axis Steering, a system currently used only in MBZ’s F1 race cars that can dynamically vary front toe tire alignment while driving.

Xentry – Pronounced “ZEN-tree”, this is the diagnostic suite built into SDS. It is designed to launch the appropriate diagnostic tool for the vehicle, such as HHT for older models, DAS and Xentry Diagnostics for the latest models. It can also launch other tools like VDOC and TIPS that require a “live” connect to MBZ corporate.

HHT - Hand-Held Tool - A dedicated hand-held diagnostic tool that reads/resets codes and programs electronics on older cars, mostly pre-MY2000, but some models like the W163 and W210 used this for their entire production.

HHTWIN - Hand-Held Tool for Windows - This MBZ's Windows-based software that replaced the physical HHT device. It is available as stand-alone software as well as being a part of SDS. Note that some later versions of SDS deleted this component.

VDOC – Also called VeDoc, is MBZ’s Vehicle Documentation database. It contains a record of every vehicle built with its options and also maintains sales and service records. Data from VDOC is used by MBZ to generate the appropriate SCN code for certain systems. It is possible for dealers to update VDOC with retrofitted options so that the SCN coding will be accurate.

TIPS – An online database of information for dealer technicians containing service bulletins and other documentation.

WIS - Workshop Information System - This is MBZ's electronic shop manual with troubleshooting guides and procedures showing technicians how to install or remove pretty much any component in the car. It is included with SDS, but also available as stand-alone software.

EPC - Electronic Parts Catalog - Like WIS, this is reference material included with SDS and available as stand-alone software, often with WIS. It includes exploded parts diagrams along with part numbers, showing the proper part number by VIN or associated with certain option codes. It also includes the data cards or "build sheets" for all modern cars up through its release date.

Multiplexer - An electronic component that physically connects the SDS computer to the car's diagnostic interface. It allows the computer software to communicate with all the car's proprietary electronics. With the proper cable attachment, it can communicate through various interfaces such as OBDII, MBZ's 38-pin connector and a few other types of interfaces used by MBZ over the years.

C3/C4/C5 - These are all versions of the SDS multiplexer. C3 is the oldest and requires a physical RS-232 port to connect to the computer. C4 and the newer C5 connect via Ethernet (crossover cable or WiFi).

OBDII - On-Board Diagnostics version II - This defines the official 16-pin diagnostic port and protocol standards required by all cars starting in 1996. The required functionality only uses 3 or 4 of the 16 pins to be able to read and reset codes from the ECM. Various manufacturers (like MBZ) have used alternate pins and proprietary protocols to be able to communicate with other electronic systems in their vehicles.

38-Pin - MBZ's older diagnostic interface, usually located in the e-box under the hood.

ECM - Engine Control Module - This computer controls engine operations by reading inputs from various sensors and then determining the proper fuel to air ratio. It may also control various engine components such as the variable-valve timing, throttle, intake manifold, cooling fan, etc. It is often called the ECU (Engine Control Unit). MBZ also refers to it as ME, “Management of Engine”.

ECU Electronic Control Unit – Generically, this is any electronic control module in the car, but it is most often used to refer to the ECM as “Engine Control Unit”

TCUTransmission Control Unit – Also called the TCM (Transmission Control Unit) or ETC (Electronic Transmission Control), this is the computer that controls the automatic transmission.

ESM Electronic Selector Module – The gearshift for an automatic transmission.

SAM Signal Acquisition Module – This is a computer module that controls various electrical components such as exterior lighting, wipers, the AC compressor, engine cooling fan, trunk lid, alarm system, etc. The SAM sends and receives information from components and driver inputs (switches, buttons, stalks) over the car’s CAN bus. The SAM also directly controls exterior lighting so it can monitor and report bulb function and electronically shut down a circuit if it detects a fault. Most modern MBZ vehicles have a front and a rear SAM, and some have multiple front and/or rear SAMs.

AAM All-Activity Module – Basically, an early version of the SAM. Instead of using a CAN bus, it is hardwired to all devices it communicates with.

CAN Controller-Area Network – This is a communication bus that allows various electronic modules in the car to communicate, much like a computer network. This helps eliminate the massive amount of wire that would otherwise be required to operate the complex functions in modern cars. Most MBZ cars have at least three CANs: interior, engine, and SRS. The multiple CANs are isolated, except for within the EIS, which acts as a hub to allow communication crossover.

EIS Electronic Ignition Switch – Also called “EZS” within SDS, this is the ignition switch. In cars without KeylessGo, this is where the key is inserted to start the engine. For KeylessGo-equipped cars, the EIS may still accept a physical SmartKey. Some KeylessGo cars use a button on the shift lever or center console, while others use a removable “cap” inserted into the EIS’s key slot that acts as the start/stop button. On those, the cap can be removed to use the SmartKey in the slot in the case of a wireless communication problem. On newer cars, there is no actual ignition “switch”; only a permanently mounted start/stop button, but that is also the EIS.

E-Box - Electronics Box - A plastic box, usually located under the hood, that contains vehicle electronic modules such as the SAM, AAM, ECM and other components. When the lid is properly closed, it is splash-proof. Some vehicles may have more than one e-box under the hood, such as those with two SAMs.

Coding – This is the process of writing firmware or setting options in an electronic module so that it works appropriately with the car. SDS calls this the components “adaptations”. Depending on the car and module, there may be various settings to enable or disable different option modules or behaviors. For example, in order for the SAM to recognize the appropriate wattage for halogen bulbs (55w) vs. HID/Xenon (35w) so that it can determine if the bulb is operating properly. Some parts require special programming before they will work with the car, such as SCN coding.

SCNSoftware Calibration Number – This is a special type of coding that programs the firmware for a module from data stored in VDOC. This requires a “live” connection to MBZ corporate to download. Components that require SCN coding are often consider theft-relevant, such as the ECM, TCU, EIS, etc. Others may only need SCN coding to ensure that the proper options have been configured based on the vehicle build sheet, such as SAMs.

Development Mode – Also called Developer Mode, this is a special option that can be enabled with SDS. Its primary purpose was so that factory engineers could test various setting without having to totally recode a module, such as those requiring SCN coding. It allows some “interesting” settings to be made, such as tweaking certain ECM and TCU parameters that can change throttle and shift behaviors. It can be used to enable some optional features, such as AMG setting on the instrument cluster. It can even be used to copy the entire coding from one module to another, even when that module requires SCN coding. This makes module replacement much simpler. Because it is intended only for factory testing, it is not enabled for dealers.

Vediamo – This is a special software add-on to SDS intended to be used by factory engineers. Like Development Mode, it has access to certain settings and options not available to dealers.

DTR Distronic – This is MBZ’s adaptive cruise control system that uses radar sensors to follow the speed of traffic ahead at a given distance.

RCL Remote Central Locking – The components that work together to allow the car to be remotely lock and unlocked via the key fob

KeylessGo – A system that uses various components to recognize a valid key in proximity of the car and allows for it to be unlocked, locked, trunk opened and engine started by pressing button on the vehicle instead of having to handle the key fob. This is often referred to as “keyless start”.

SBC - Sensotronic Brake Control - This is unique "brake by wire" system MBZ used in a few models (W211 E-class, W219 CLS, and R230 SL). It still uses fluid to hydraulically operate the wheel cylinders, but instead of pressure being generated by a master cylinder operated by the brake pedal, the pressure is created by an electric pump. The SBC computer is in full control of braking and distributed pressure at varied rates to individual wheel cylinders. There is still a tiny, non-assisted master cylinder than is operated by the brake pedal for emergency situations if SBC fails. For SBC-equipped cars, this also manages the ESP system.

ESP - Electronic Stability Program - A system that provides the functions of traction control, stability control and anti-lock braking and emergency braking assist . It uses inputs from various sensors (individual wheel speed, lateral acceleration, accelerator input, steering wheel position, etc.) and can control engine speed and individual wheel braking. On non-SBC cars (i.e. most cars) it uses a small pump to create and store pressurized brake fluid as needed for control of the brakes without pedal input.

ABC - Active Body Control - A special hydraulic suspension system that uses an engine-driven pump to create pressurized fluid to control both the firmness and travel of the shocks. ABC is an "active" suspension system in that it can instantly change how individual shocks react to road conditions. It can allow the car to be raised for driving on rough roads and for additional ground clearance, or lowered for better handling and aerodynamics. It can also make the car handle better be greatly reducing body roll and keeping the car flat in curves as well as eliminating squat and dive. ABC was available on the R230 and R231 SL, the W219 CL, and the W220 S-Class.

AIRmatic - This is similar to ABC, but uses air instead of hydraulic fluid to adjust the shocks. It is not an "active" system as it cannot adjust quickly enough, but it can raise and lower the vehicle and it can adjust firmness.

TPC - Tire Pressure Monitoring - Two different systems are used. The "high-line" TPC uses individual electronic sensors mounted in each wheel as part of the valve stem. These sensors use RF transmitters to report the pressure to a vehicle-mounted receiver. The "low-line" version uses data from ESP to detect when tires are not rotating at the same speed when traveling straight and thus alerts the driver to a potential low-pressure situation.

HRA - Headlight Range Adjustment - When equipped with HID/Xenon headlights, this system uses sensors on the front and rear suspension (usually attached to the anti-sway bars) to determine the angle of the body relative to the road. This is primarily used to lower the angle of the headlights when the rear of the vehicle is loaded to prevent blinding oncoming drivers.

OCP - Overhead Control Panel - The interior control panel located on the cockpit ceiling, containing controls for features such as map lights, the sunroof, TeleAid/mBrace, microphone, etc. It may also contain temperature sensors used by the ACC.

UCP - Upper Control Panel - This is one of the control panels on the dash that usually sits above the ACC and audio controls. It may contain buttons for things like hazard lights, seat heaters, door locks, headrest control, etc.

LCP - Lower Control Panel - A control panel that is located lower on the dash, usually containing the ACC panel.

BCM - Battery Control Module - For vehicles equipped with multiple batteries, this module controls charging and power supply from them. For example, cars equipped with SPC will have two batteries - one used only for the starter and second one used all other vehicle power needs. This is necessary because SBC requires electrical power to operate the brakes and this allows the main battery, which powers the system, to be unaffected if the engine was difficult to start.

ICM - Instrument Cluster Module - Just as it sounds, this is the instrument cluster that contains gauges for vehicle speed, engine speed, fuel level, coolant temperature, etc.

MFD - Multi-Function Display - This is an LCD screen (or multiple screens) within the ICM that displays various vehicle information. It can be used interactively to change some settings, such as enabling daytime running lights, automatic seat adjustment for "comfort" access, etc. I can also display detailed information such as station and song title from the radio, or simple direction information from navigation. Odometer, selected gear, and trip computer data us displayed n the MFD, too.

SCM - Steering Column Module - All of the electronic controls and devices on the steering column and steering wheel feed into this module. It sends and receives data over the CAN bus so that these devices can interact with the rest of the vehicle. For example, the volume control buttons on the steering wheel are connected to the SCM. When Volume+ is pressed, the SCM sends a message over the CAN that the radio receives and then responds to by increasing the volume.

PTS - Parktronic System - A sonar-based system that senses objects close to the front and rear of the vehicle and alerts the driver. This system typically only operates at low speeds and close distances (a few feet).

DCM - Door Control Module - These modules, located in each door, connect to all of the electronic devices in that door. It transmits data over the CAN bus when switches on the door are activated, and also responds to input from other systems in the care. Examples include operating the door lock when an unlock or lock command is received over the CAN bus, or sending a command to the passenger door controller to operate its window regulator motor when the button for that window is pressed on the driver's door.

ESA - Electronic Seat Adjustment - This system includes several modules. It controls the power adjustment of the seats and the steering column, as well as managing the memory for those positions. It involves controllers under the seats, the DCMs, as well as motors in the seats and steering column. The seat controllers and DCMs communicate over the CAN bus.

PSE - Pneumatic System Equipment - Some devices within the vehicle are operated pneumatically (via vacuum or pressure) as opposed to electrically. The PSE encompasses those devices, which can include seat lumbar and bolster adjustments, door and trunk locks, as well as lowering of rear headrests via a dash button. On vehicles with lumbar/bolster adjustments, and on vehicles with pneumatic locks, there is usually a trunk-mounted electric PSE pump used to provide air pressure. For vehicles that do not have that equipment but can lower the rear headrests via a dash button, engine vacuum us generally used instead of a dedicated pump.

ACC - Automatic Climate Control - This includes all components used to manage the cabin ventilation and air temperature, including the air conditioning system (compressor, evaporator, condensor, etc.), fan, heater core, ducts, dampers, filters and the dahs-mounted control panel.

RVC - Roll Bar Controller - Also sometimes referred to as the convertible top controller, this module manages the operation of the electronic and hydraulic components used to open and close the soft-top (on cabriolet vehicles) or the Vario roof (on roadsters with foldable hardtops). It also controls the automatic roll bar that can be deployed when a rollover is detected. For cabriolets with rear seats, this unit also acts as the DCMs for the rear windows and seatbelt presenters.

AHE - Trailer Recognition - For vehicles equipped with a trailer towing package, this module controls the lights and braking system. On some vehicles, it may not be a separate module, but instead is integrated into the rear SAM.

DoIP - Diagnose over IP - The vehicle is capable of hooking to a remote service tech on the web, and getting diagnosed on the fly. Some of the newer SDS now claim that ability.

Coupe/Convertible Forums Moderator
CURRENT: 2011 SL550 FORMER: C300, ML350, CLK550 Cabriolet, C240, ML320, 300TD
24,974 Posts
Discussion Starter · #2 · (Edited)
Feel free to reply to this thread with with any additions or corrections. Just for the sake of keeping the thread clean, I'll delete those comments once the main post has been updated.

Edit log:

2021-09-01 - Some updates and a typo corrected (thanks @Lou Erickson for that input).
2021-09-20 - Corrected 30-pin to be 38-pin (thanks @millweigh for catching that).
2022-02-06 - Corrected typo under Developer Mode (credit to @MNSL550)
2022-02-06 - Add DoIP (thanks to @wallyp)
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