Understanding the Central Gateway Control Unit in a Mercedes-Benz Vehicle

Mercedes-Benz Central Gateway Module ZGS (CGW) may fail, causing various warning lights or systems to stop working. Mercedes Central Gateway module is the hub that allows communication between various modules. Mercedes ZGW Gateway control module stores data for Mercedes ASSIST or ASSYST plus.

Problems with this module can be challenging to diagnose, especially if you are not specialized in Mercedes-Benz vehicles.

What is the Mercedes-Benz Central Gateway control unit or module?

Mercedes Benz Central Gateway Module

The Central Gateway Control Unit, also known as the CGW, ZGS, is an essential component in the communication network of a Mercedes-Benz vehicle. It acts as a hub for multiple control units, connecting and exchanging data between systems such as the engine control unit, the instrument cluster, and various comfort and safety systems. The Central Gateway Control Unit is responsible for processing and distributing sensor data, controlling actuators, and monitoring the system for faults. The CGW also has the ability to diagnose and repair faults within the communication network, making it a critical component for ensuring the proper functioning of the vehicle. In some models, the CGW also controls features like keyless entry, power windows, and other comfort features.

Mercedes Central Gateway Module is the main hub that communicates with various ECUs and modules, including seat modules, front, and rear SAM, audio gateway modules, etc. Depending on how and what component of the Mercedes Central Gateway module fails, you will notice various lights and disabled systems.


bad mercedes central gateway module cgw zgs warning lights

Symptoms of a bad Mercedes Central Gateway module usually vary from car to car.

No Communication

A common symptom of a bad Gateway Module is that there is no communication between an OBD-II scanner and one or more modules. Control modules that communicate via the Central Gateway module do not respond if the Gateway Module has failed. The engine will sometimes start and run fine, but the vehicle may go in limp mode.

Intermittent Electrical Issues

The central gateway control module can also allow systems to work and shut them down at unpredicted times due to a bad or corroded connection or terminal. A bad CGW can also cause the engine to randomly shut off even when driving.

Random warning lights and messages

You will have several warning lights stay ON on your cluster, and several features stop working. Below is a list of warning lights and problems you may notice if your Mercedes Central Gateway Control module fails. This is a partial list, and symptoms can vary between Mercedes models such as C, E, S, CL, CLK, CLS, ML, G, GL, R, SL Class.

One or more of the following lights may come on.

  • SRS/Airbag light ON
  • Check the Engine Light ON
  • ABS or ETS light on
  • Battery Warning Light ON
  • Low oil light
  • Brake Light ON

Disabled Systems

One or more of these systems may stop working when the Mercedes Central Gateway Module fails.

  • Radio / COMAND not working
  • Both front seats not working
  • Heated seats
  • Keyless Entry
  • Rear liftgate
  • Wipers
  • Turn signals
  • Lights
  • Instrument Cluster
  • Heated Seats
  • Sunroof

Common Problem


Mercedes Central Gateway Module may fail due to water damage. It can also fail to internal software or hardware defects. Damage to the Mercedes Central Gateway Control module can be caused by a blocked drain valve in the trunk floor.

mercedes blocked drain valve causing failure of central gateway module cgw

On some models, the Central Gateway Module is mounted on the vehicle’s trunk floor, where water can easily damage the unit.



If the Mercedes-Benz gateway module has failed and doesn’t communicate with other ECUs, it will need to be replaced. Cleaning a Central Gateway Module terminal can be attempted, but it is rarely successful.

A new CGW module can be purchased at the dealer or online. You must get the CGW module coded properly with Star Diagnostic Scanner. The Star diagnostic scanner will need to have a subscription to complete online coding.

If you replace the bad CGW with a new one, you will have systems that will not work because they are not coded in the CGW module. CGW/ZGW Gateway control module stores vehicle service history, VIN, and car mileage. You will need to code the original miles and VIN in the new ZGW module by cloning the information from your old Mercedes ZGW control module. If the ZGW data cannot be read, manual coding can be performed by the dealer or a Mercedes mechanic.

For example, the power seats may not work because they are not coded in the new CGW module. Keyless entry may not work because it needs to be coded in the CGW module. You need to code the CGW module and tell what modules and systems are installed on that vehicle.

CGW Part Numbers

Below you will find a partial list of Mercedes-Benz Central Gateway Control Module part numbers. This is for reference only; you should never order parts based on this list. If you need to figure out the part number of your Mercedes-Benz, call a dealer and provide your vehicle’s VIN.

  • 2305407145 – 2007 Mercedes-Benz SL550 R230
  • 2115403545 – 00-06 MERCEDES S-CLASS
  • 2115405745 – CLS550 CLS63
  • A1715409245 – 2008 MERCEDES SLK280
  • 2205402845 – 2006 MERCEDES BENZ R230
  • 2115403545 – 00-06 MERCEDES CL500
  • A1645406745 – 2006 2007 2008 2009 Mercedes ML-Class
  • 2114452000 – MERCEDES 211 E320
  • 2115407145 – 06-2011 MERCEDES CLS550 W219, CENTRAL GATEWAY MODULE
  • A2205402645 00-06 Mercedes W220 Central Gateway Body Control Unit Module
  • A 221 540 27 62 , A2215402762 – W221 S550 S63
  • 2215408362 Mercedes Cl63 Cl65 Amg
  • 1715405045 – R171 SLK350

We hope you find the Mercedes-Benz Central Gateway Control Module Failure guide helpful. Check these troubleshooting and repair guides for more help on your Mercedes-Benz.


  • Rushit Hila • ASE Certified

    Rushit Hila, an ASE-certified engineer (G1 Automotive Maintenance and Repair), brings over two decades of hands-on experience in the automotive world to his writing. With a strong educational background, including a Master of Science in Engineering and a Bachelor of Science in Engineering, he has honed his skills and expertise through years of practical work. As a respected authority in the field, Mr. Hila is dedicated to offering insightful and valuable content that resonates with both vehicle owners and mechanics.

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  1. Hi Mr.Hila,

    What if I replaced with the exact part number? Will it work as intended?
    In my case, mine is MB ML350 2006 which has CGW part number A1645406745. My CGW was water damaged during the flooding.
    I purchased a used CGW coming out of MB ML320 2007 which also had the same part number A1645406745.
    I have not installed and tried it out on my car yet and I would like to check here in advance if it will work as I do not want to further complicate the situation. Thank you.

    1. You can install it.The vehicle should start. There may be some simple coding that may need to be updated. If needed you will know becasue there may be a system or two that won’t work. But overall the vehicle should turn on, start with the CGW that you noted.