fbronc69

Does anybody know how the central gateway works. I have a 1.5 amp draw thru the fuse for the central gateway ( have to pull it to keep the battery from going flat). I cleared all codes and nothing new is coming up. I did take the module out and it looks very clean.


Thanks for your help.

bbirdwell

It is literally the central gateway connecting the Interior and Engine CAN buses. Stores maintenance info and configuration info for the car's digital modules. When replacing, pull info from CGW, then program that info into the replacement CGW. STAR/Xentry walks one through the process.

CaliBenzDriver

STOP troubleshooting digital systems by pulling fuses.

You need to understand what is upsetting your gateway. It stays awake because of junk traffic.

One of your module is in crisis mode.

Usually this will be CAN-B modules and more specifically the poor door controllers connections.

SAM's are very qualified at creating troubles once out in a swamp situation.

Work with a good scanner to query status. (LAUNCH cReader Elite Bz)
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nd-photo.nl

You can also rewire so that it only runs on ignition, but I think @CaliBenzDriver has the better proposition

CaliBenzDriver

I suggest you troubleshoot what is causing your problem without creating extra new problem.

Normally SAM manages all modules power on/off as needed.

With that being said:
I AM A BIG FAN OF BATTERY DISCONNECT if car is to be parked longer than a 3 weeks period.
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FYI : SAM/CGW are not particularly stable modules. THEY BENEFIT FROM REBOOT about twice a month to easily restores normal processing speed with lower latency.

FLASHBACK

CaliBenzDriver Interesting idea, how do you Reboot the SAM/CGW?
Battery disconnect or is there a way in Xentry?

Plutoe

I think someone is very confused with computer terminology and reading between the lines disconnecting and re connecting the battery someone thinks is rebooting when in this case no operating system or data is reloaded the switches are either on or off

CaliBenzDriver

Yes simply Batt GND disconnected for 15mn (do NOT short both sides to speed up discharge... nope!).

F-SAM/CGW are up non stop 24x7 365 days. Unlike other modules they never get restarted.

CGW is the most busy gateway module of the whole chassis to establish coms between the every modules across different networks. It tracks connections and runs out of clear RAM aka. "memory leak". This slows down transfers and causes latency.
I don't know of a way to reboot it from Xentry unless it has a logged DTC that can be cleared, then yes.

The performance issue I mentioned is not tracked thus has no associated fault.

CaliBenzDriver

Mr. Plutoe, thank you for your efforts understanding this is not about toggling switches... it's all about network throuput ie. lost data bandwidth.

Consider the network map and the individual module functionalities interacting across network through gateways.

I have recently evidenced the engine and tranny timings are directly impacted by external latencies. Let's that sink in as much as possible.

Rebooting chassis is like Tylenol...
It temporarily relief the consequences without adressing any of the multiple causes.

This is based on the unproven assomption that what's bad in W212 was already bad in W211.

Is that nice help?


+++ Network map actually shown in Post#2