W221 Electrical Gremlin. Help!
Thread Starter
Newbie
Joined: Dec 2025
Posts: 7
Likes: 2
From: Texas
2010 Mercedes S550
W221 Electrical Gremlin. Help!
Hello Everyone!
I’m having an interesting electrical issue, my 2010 S550 with only 77k miles has no communication with any module through OBD, no start no crank and flickering screen with errors (see video), I’ve put a brand new battery no luck, I’ve bought another gateway to plug in and still same flickering symptoms.
update: we have established connection after unplugging the headlights and connecting the original gateway, we could go into every module except eis so we sent our eis away to a tech and they found that the chip is shorted inside the eis so they replaced it, we now plugged everything in and got a new problem, when we go to crank both screens flicker like crazy as if there is a short somewhere and obviously again no crank!
what could this be?
YouTube link: https://youtube.com/shorts/oFyDjytk630?si=lwxzRTqpSDT-4B-x
I’m having an interesting electrical issue, my 2010 S550 with only 77k miles has no communication with any module through OBD, no start no crank and flickering screen with errors (see video), I’ve put a brand new battery no luck, I’ve bought another gateway to plug in and still same flickering symptoms.
update: we have established connection after unplugging the headlights and connecting the original gateway, we could go into every module except eis so we sent our eis away to a tech and they found that the chip is shorted inside the eis so they replaced it, we now plugged everything in and got a new problem, when we go to crank both screens flicker like crazy as if there is a short somewhere and obviously again no crank!
what could this be?
YouTube link: https://youtube.com/shorts/oFyDjytk630?si=lwxzRTqpSDT-4B-x
Last edited by 221gremlin; Jan 7, 2026 at 10:58 PM. Reason: Update
MBWorld Fanatic!
Joined: Aug 2014
Posts: 5,322
Likes: 1,678
S500
Hello Everyone!
I’m having an interesting electrical issue, my 2010 S550 with only 77k miles has no communication with any module through OBD, no start no crank and flickering screen with errors (see video), I’ve put a brand new battery no luck, I’ve bought another gateway to plug in and still same flickering symptoms.
what could this be?
YouTube link: https://youtube.com/shorts/oFyDjytk6...xzRTqpSDT-4B-x
I’m having an interesting electrical issue, my 2010 S550 with only 77k miles has no communication with any module through OBD, no start no crank and flickering screen with errors (see video), I’ve put a brand new battery no luck, I’ve bought another gateway to plug in and still same flickering symptoms.
what could this be?
YouTube link: https://youtube.com/shorts/oFyDjytk6...xzRTqpSDT-4B-x
confused gateways give no comms to the ODB2 socket - and a battery reset (disconnect for 20 min) often sorts it out
however the other fun you are having isn't just a battery reset - replacing the other baby motorcycle battery behind the ignition switch likely not a bad idea
look for blown pre fuses and as other's mention poor earths
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,142
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
Hello Everyone!
I’m having an interesting electrical issue, my 2010 S550 with only 77k miles has no communication with any module through OBD, no start no crank and flickering screen with errors (see video), I’ve put a brand new battery no luck, I’ve bought another gateway to plug in and still same flickering symptoms.
what could this be?
YouTube link: https://youtube.com/shorts/oFyDjytk6...xzRTqpSDT-4B-x
I’m having an interesting electrical issue, my 2010 S550 with only 77k miles has no communication with any module through OBD, no start no crank and flickering screen with errors (see video), I’ve put a brand new battery no luck, I’ve bought another gateway to plug in and still same flickering symptoms.
what could this be?
YouTube link: https://youtube.com/shorts/oFyDjytk6...xzRTqpSDT-4B-x
Put the original CGW back in as it may change things if it is the issue with the bad connections between the harness pins and the board, like I had the issue with. Re-connecting the old CGW may move the pins and allow better connection again.
This may be the cluster issue too.
Thread Starter
Newbie
Joined: Dec 2025
Posts: 7
Likes: 2
From: Texas
2010 Mercedes S550
Update!
update: we have established connection after unplugging the headlights and connecting the original gateway, we could go into every module except eis so we sent our eis away to a tech and they found that the chip is shorted inside the eis so they replaced it, we now plugged everything in and got a new problem, when we go to crank both screens flicker like crazy as if there is a short somewhere and obviously again no crank!
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,142
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
update: we have established connection after unplugging the headlights and connecting the original gateway, we could go into every module except eis so we sent our eis away to a tech and they found that the chip is shorted inside the eis so they replaced it, we now plugged everything in and got a new problem, when we go to crank both screens flicker like crazy as if there is a short somewhere and obviously again no crank!
Trending Topics
Thread Starter
Newbie
Joined: Dec 2025
Posts: 7
Likes: 2
From: Texas
2010 Mercedes S550
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
MBWorld Fanatic!
Joined: Feb 2012
Posts: 2,641
Likes: 1,224
From: Phoenix
222 S-65
Or maybe... Just maybe it; at the tender age of 15 is old enough that a starter, Central Gateway, EIS or any of the other myriad issues that happen that can be a real treat to sort out have failed.
May the Force be with you Friend.
May the Force be with you Friend.
MBWorld Fanatic!
Joined: Aug 2014
Posts: 5,322
Likes: 1,678
S500
if you are running a late spec CGW that is not programmed with the correct software iteration and coded to suit options on the car - it can not operate correctly - indeed I presume damage could be achieved
Super Member
Joined: Oct 2023
Posts: 568
Likes: 197
W221 S500
Never flooded? Are you sure about that? Lift the front carpets and check for ANY signs of moisture in the CANBUS junctions and treat it accordingly.
For testing purposes, the CGW can be swapped for another. True some features may not function, unless it's correctly optioned. From experience this is easily done using Xentry... However, you cannot change Vehicle Vin or Mileage after the initial programming of the CGW and you will get a code for the VIN mismatch.
For testing purposes, the CGW can be swapped for another. True some features may not function, unless it's correctly optioned. From experience this is easily done using Xentry... However, you cannot change Vehicle Vin or Mileage after the initial programming of the CGW and you will get a code for the VIN mismatch.
Thread Starter
Newbie
Joined: Dec 2025
Posts: 7
Likes: 2
From: Texas
2010 Mercedes S550
Latest update. Car started
Hello Everyone!
I’m having an interesting electrical issue, my 2010 S550 with only 77k miles has no communication with any module through OBD, no start no crank and flickering screen with errors (see video), I’ve put a brand new battery no luck, I’ve bought another gateway to plug in and still same flickering symptoms.
update: we have established connection after unplugging the headlights and connecting the original gateway, we could go into every module except eis so we sent our eis away to a tech and they found that the chip is shorted inside the eis so they replaced it, we now plugged everything in and got a new problem, when we go to crank both screens flicker like crazy as if there is a short somewhere and obviously again no crank!
what could this be?
YouTube link: https://youtube.com/shorts/oFyDjytk6...xzRTqpSDT-4B-x
I’m having an interesting electrical issue, my 2010 S550 with only 77k miles has no communication with any module through OBD, no start no crank and flickering screen with errors (see video), I’ve put a brand new battery no luck, I’ve bought another gateway to plug in and still same flickering symptoms.
update: we have established connection after unplugging the headlights and connecting the original gateway, we could go into every module except eis so we sent our eis away to a tech and they found that the chip is shorted inside the eis so they replaced it, we now plugged everything in and got a new problem, when we go to crank both screens flicker like crazy as if there is a short somewhere and obviously again no crank!
what could this be?
YouTube link: https://youtube.com/shorts/oFyDjytk6...xzRTqpSDT-4B-x
SOLVED!
