Home > Popular Articles > Mercedes-Benz Star Diagnostic Scanner Tool – Everything you need to know
YouTube video

Mercedes-Benz Star Diagnostic Scanner Tool – Everything you need to know

If you own a Mercedes-Benz and are looking to do your repairs, you may have heard about Mercedes Star Diagnostic (SD) scanners C3 and C4. This article discusses the advantages of the Mercedes Star Diagnostic scanner, including things you need to remember before buying an MB Star Diagnostic scanner. A list of top alternative scanners to Star Diagnostic is included as well. Note that this article is not written to approve or sell any scanners mentioned here, including Star Diagnostic Scanner. We share our experience and research of diagnostic scanners and hope to help you, the Mercedes-Benz owner, who is looking to perform your own MB repairs and diagnostics.

Mercedes Star Diagnostic Tool and Software

Let’s first explain what Star Diagnostic SD (C3 or C4 SD Connect) tool is for those wondering. This diagnostic scanner is used at Mercedes-Benz dealerships and some auto repair shops. Independent shops can also purchase it. These scanners include the hardware and Xentry, the software used to troubleshoot the problems in any Mercedes-Benz. Original units can be purchased at STAR Tekinfo, the official Mercedes-Benz site offering technical documents, special tools, and diagnostic software.

Mercedes-Benz Scanner MB-Star Diagnostic allows you to read and erase fault codes from any control unit in your Mercedes-Benz. With the Star Diagnostic scanner, you can read the actual configurations in each system, stream real-time sensor data, activate sensors and perform SCN online and SCN offline coding and programing.

Mercedes Star Diagnostic for Sale

Check  Price on Amazon Check Lowest Price on eBay

If you search the online resellers, you will find Mercedes Star Diagnostic C3 and C4 listed for sale. You must be careful when buying online, as many of these units may not be original.

Advantages of Star Diagnostic Scanner

The dealer uses this scanner, allowing you to access and troubleshoot any system or control system in your Mercedes-Benz. Activate any sensor in the car, perform initiation tests, stream live sensor data, and read and clear fault codes. This is a must if you own a shop focusing on Mercedes-Benz cars. Get it via official channels so that you can perform online SCN coding. All MB SD control units are accessible, like engine ECU, ABS, Airbags, SRS, Aircon, Immobilizer, Keyless Entry, and the other 40+ control units used in MB cars. You can Read / Delete Faults, Live Data, perform sensor actuation, read current configuration, initialization, and more.

Things to consider before you buy one!

If you are looking to purchase a Star Diagnostic System with Xentry for Mercedes-Benz there are a few things you need to consider.

Learning Curve: To use the diagnostic scanner properly, you must learn to use the Xentry software. While reading, clearing fault codes is not very difficult; besides that requires proper training. Yes, you can find a few guides online on performing certain programming using Xentry, but if you don’t perform the programming accurately, you may end up causing more problems than you solve.

Consider Genuine Scanner: The only problem is that they are expensive and require a yearly license. If you are considering buying a clone of the scanner made in China, keep the following concerns in mind.


SCN Online Coding: Unless you buy the scanner from the official Mercedes-Benz source, you cannot perform SCN coding of control units. That’s because the Mercedes Star Diagnostic scanner will try to connect to the Mercedes-Benz database to verify the SCN code to program certain control units. That is not possible unless you have purchased a valid license. With that said, there may be some basic coding and programming of control units that can be done, but this programing can also be performed with other advanced scanners.

Mercedes Star Diagnostic Problems with Software (Xentry) VM Ware Installation: All the setups you see for sale that state that they use VMware environments are not legitimate hardware and software. Besides the fact that these scanners are not legal copies, they are also prone to crashing and run much slower than direct Windows installations. Yes, you are required to have a Windows XP with a serial port for the MB Star Diag C3 scanner. Many VMWare Mercedes Star Setups experience problems, some of which you can see posted on this site: MB SD C4 C3 problems and solutions.

License: To get the full features of the Mercedes Star diagnostic scanner, you need to sign up for a yearly subscription and pay a license fee. This is not financially feasible if you only work on one or two Mercedes-Benz models. If you buy a cloned version of the scanner, the Xentry software key will expire in a few years, and you will not be able to use your scanner at all.

Mercedes Star Diagnostic Scanner C3 & C4 Alternatives

In our opinion, there are better alternatives for those who like to do their troubleshooting. Whether you are a repair shop or a Mercedes-Benz owner, consider these scanners as well. We do not endorse the following OBD II / CAN scanner brands. Links to Amazon and eBay listings are provided to check current prices.

YOUCANIC Full System Scanner

YOUCANIC full system scanner is one of the best alternatives to the Mercedes Star Scanner. This scanner is much less expensive than the Mercedes Star Diagnostic C3 or C4.

This handheld diagnostic scanner is dedicated to Mercedes-Benz but also works on their makes. It is nice that it doesn’t require a laptop. Using the scanner is very straightforward, even if you have never used one of these scanners before. It is affordable for Mercedes-Benz owners who want to do their diagnostics and repair.

It covers over 40+ control units and also has coverage for the latest Mercedes-Benz models. It can also be updated. It can read any system on Mercedes-Benz models manufactured after 2000, such as transmission TCU, ESP, ETS, ABS, Air Conditioner, Door Control Unit, SBC brake, Brake Control Unit, Airmatic, and more.

It offers bi-directional support and active tests for testing purposes.

This unit’s disadvantage is that it will not work on older models past 1993. It will not work on models that require a 38-pin connector, such as the E 320 and CLK 430 unless you get the 38-pin to OBD2 adapter separately. In these models, it can only read the ECU (check engine light).

Autel MaxiDAS Full System Scanner

This is the perfect solution for auto repair shops. It is more expensive than a YOUCANIC scanner, but it has three main advantages: 1. It can troubleshoot most car models and makes, including Honda, Toyota, Audi, BMW, Lexus, Hyundai, etc. 2.

It can diagnose multiple systems such as engine, transmission, airbag, air condition systems, traction control, anti-lock brakes, and all other major systems. 3. It can perform sensor live sensor stream, sensor activation, and programming.

Disadvantages: This is a little pricey for owners, but this is the least expensive professional scanner if you own an auto repair shop. Scanners that have similar capabilities such as Snap-on souls cost four to five times more than Autel DS708.


Mercedes Benz MB Star C3 vs. C4

MB Star C3 requires a laptop to troubleshoot your Mercedes-Benz via Xentry software. While it is slower than MB Star C4 on paper, it has proven to be a reliable and robust scanner not plagued with WiFI connectivity issues like the Star C4.

MB Star C4 is the latest Mercedes-Benz wireless multiplexer that can connect to your PC via a wireless connection. Being the latest Diagnostic Scanner for Mercedes-Benz, it works faster once you resolve any connectivity issues.

Frequently Asked Questions

What is DAS? – Diagnostic Assistance System – This is the full diagnostic system for Mercedes-Benz vehicles. All functions for diagnosis, including reprogramming, configuration, initialization, fault diagnosis, and guided diagnostic tests, are contained within DAS.

    • All control unit software (reprogramming calibrations) is contained within the DAS software and distributed monthly via DVD media.
    • All-access and functionality required regarding the configuration via SCN Coding and/or CVN Coding are covered.

What is WIS-NET? – Workshop Information System – This is the complete workshop information system developed by DaimlerChrysler for servicing Mercedes-Benz vehicles. Contained within are installation instructions, procedures, and functional and technical specifications. There is some linkage between certain procedures in DAS to respective documents in WIS.

What can Mercedes Star Diagnostic Tool do? The system offers total diagnostic coverage of all engine, chassis, and body systems:

  • Reading and re-setting of diagnostic trouble codes (DTC)
  • Real-time reading of dynamic data
  • Full component activation clearing and re-setting of adaptation values
  • Coding of all engine, chassis, body, and instrumentation modules
  • Key configuration
  • Procedure for fitting Mercedes- Benz accessories through the D2B ring and MOST bus
  • Total ASSYST / ASSYST + control (Active Service System) to update on-board service history

What is Workshop Green Key? This is a unique one-time key from the factory which is necessary for certain situations such as: 

  • Disabling a key track
  • Replacing the ECU
  • Replacing security-related control units
  • Replacing EIS

Typically the workshop key and EIS must be ordered together, and the green key is used to perform the final programing of the EIS.

What does it mean to marry a VIRGIN ECU and EIS? The ME (ECU=Engine Control Unit)  and  EIS (Electronic Ignition System) control modules are electronically permanently married to each other after 40 engine starts. There is no factory procedure to undo this. This means a used engine EIS or DAS control unit cannot be used on another vehicle. A new control unit can be installed for testing, provided the 40 engine starts are not exceeded. Note that the new control unit must be variant coded before being used. If the 40 engine start cycles are not completed successfully, resetting the counter to 0 (removing the version coding) is possible if you disconnect the power from the ECU for at least 45 minutes. 

What model years does Star Diagnostic Scanner work with? The Star Scanner should work on cars from 1989 to 2015 for Mercedes Cars, Buses, Trucks, Sprinter Vans, Smart cars, Etc.
What can I do with Star Diagnostic SD Connect Scanner C3 & C4? 

  • Reading/Erasing Trouble Codes
  • Read Live Data
  • Adaption of Modules
  • Coding/Programming of Modules
  • Component Testing
  • Maintenance Information Consultation


What is Xentry? New software released by Benz Company after 04/2009 by diagnosis new cars. WIS.net: Workshop Information System EPC.net: Electronic Parts Catalogue STAR UTILITIES: the movement management system and self-test DAS: the automatic Diagnosis Assistance System ST Finder 2008: Part location finder

What is Smart TAN Code? It opens a special function in the DAS program with Smart cars 450/451/452/454 Developer model: Mercedes-Benz engineer mode, remove limitations and open more functions.

What is the Benz Disassembly system? Video lessons to teach you how to remove each part from Benz cars with details order steps.

Which control units can MB Star Diagnostic Scanner with Xentry troubleshoot? 

  • Engines (All Gasoline & Diesel Systems)
  • Transmissions and Electronic Selector Modules
  • Airmatic and Active Body Control Suspension Systems
  • Traction Systems: ESP / ASR / ETS / ABS / BAS / SBC braking systems
  • Supplementary Restraint Systems (SRS) / Airbag, All body modules OCP / UCP / LCP / SCM / SKF / KFB / RCM / DCM’s
  • Drive Authorisation System
  • Sam (Signal Acquisition) Modules
  • Electronic Ignition System (EIS)
  • Pneumatic System Equipment and ATA functions
  • Air Conditioning/climate control Systems
  • Instrument Cluster
  • Tyre Pressure Control
  • Parktronic System
  • Keyless Go
  • D2b Command & Audio Gateway (D2B and MOST networks)
  • TV Tuner
  • Headlamp Range Adjustment
  • Seat Electronics
  • Rvc, RST & Vario Roof modules
  • Automatic Clutch System ACS
  • M-Class Body Modules (AAM / EAM / DAS / SEM / VG Transfer Case)
  • Assyst & ASSYST + systems

Mercedes Diagnostic Scanner Tool C3 and C4 Resources



  1. R.w.wickramanayaka

    we are running a work shop for servicing MB vehicles. we need to have scan tool ( star ) for our day today works .we would like to no about the cost & the other conditions for supply, since we are not a local agent for the MB vehicles.

  2. Please, how can I get the original C4 scanner that performs SCN coding and all other functionalities from Germany? Also, can this scanner work in any part of the world?

  3. Great article,it is useful to me and others,please just keep it….


Leave a Reply

Your email address will not be published.

All rights reserved Notice: CLOUD