C-Class (W204) 2008 - 2014: C180K, C200K, C230, C280, C300, C350, C200CDI, C220CDI, C320CDI

whattahell is a 30g fuse on 2011 c300

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old May 15, 2024 | 11:56 AM
  #1  
raverx3m's Avatar
Thread Starter
Member
15 Year Member
 
Joined: May 2009
Posts: 209
Likes: 4
2011 c300 4matic
whattahell is a 30g fuse on 2011 c300

im having a parade of random electrical codes that im assuming all spawn from that mistery 30g circuit.
and i cant find any reference to it on forums or google.
im gonna list the codes maybe someone can help me figure out whats happening

fault 03 OCP-overhead control panel the interior illumination has a malfunction .there is a short (everything on panel seems to work ok)
974914 the rearinterior illumination has a short circuit to ground or an open circuit
fault 01 rear sam-rear signal acquisition and actuation module
fault 01 dcu-rf-right front door(everything on the door seems to work ok)
fault 05 aac-air conditioning (n22/7) (ac seems to work ok)

a15911 circuit 30G has a malfunction there is a short to ground
b224b98 control unit "rear signal acquisition and actuation module has a malfunction the component or system has overtemperature.
9dd015 the output for the mirror heater has a malfunction there is a short circuit to positive or an open circuit
90a251 the actuator motor to the left blend air flap has a malfunction the component is not programmed
90a951 the actuator motor for the right blend air flap not programmed
90f751 the actuator motor for air flap left defroster vent has a malfunction not programmed
912b51 the actuator motor for the ram air recirculation flap not programmed
917851 the actuator motor for the air distribution flap not programmed
917851air distribution flap not programmed

i have old autel ds708 shop scanner
Reply
Old May 23, 2024 | 11:26 AM
  #2  
raverx3m's Avatar
Thread Starter
Member
15 Year Member
 
Joined: May 2009
Posts: 209
Likes: 4
2011 c300 4matic
anyone know?
Reply
Old May 23, 2024 | 11:42 AM
  #3  
TimC300's Avatar
MBWorld Fanatic!
Community Builder
Liked
Loved
Community Favorite
 
Joined: Aug 2023
Posts: 3,687
Likes: 1,107
From: MA Coast
W204 2010 C300 4matic Sport M272
I think its part of the wiring harness all over the car. Based on your fault codes i would be inspecting the rear SAM wiring, check for any faulty wiring. Wonder if there is water damage since the SAM is right below where the trunk will leak.
Reply
Old May 23, 2024 | 03:18 PM
  #4  
raverx3m's Avatar
Thread Starter
Member
15 Year Member
 
Joined: May 2009
Posts: 209
Likes: 4
2011 c300 4matic
I work at a tint shop and yes the fuse box in mercedes has been always positioned right under water runoff.
they had this issue since late 90s.
and never fixed it.
where would i find reference to that circuit possibly?
google shows nothing for c300
Reply
Old May 23, 2024 | 04:09 PM
  #5  
TimC300's Avatar
MBWorld Fanatic!
Community Builder
Liked
Loved
Community Favorite
 
Joined: Aug 2023
Posts: 3,687
Likes: 1,107
From: MA Coast
W204 2010 C300 4matic Sport M272
30g is the specific circuit. You have to look at the wiring diagrams for that circuit.

I can find circuit 30g in the headlight diagram for example:


Reply
Old May 23, 2024 | 06:39 PM
  #6  
TimC300's Avatar
MBWorld Fanatic!
Community Builder
Liked
Loved
Community Favorite
 
Joined: Aug 2023
Posts: 3,687
Likes: 1,107
From: MA Coast
W204 2010 C300 4matic Sport M272
I stumbled upon a W204 training manual that mentions Circuit 30g. Doesnt explain much but maybe will give you a lead on what to check. Heres the link to the page of the training manual: https://www.mersec.net/266/on_board_...anagement.html

Mentions it under Exercise.


Reply
Old Aug 31, 2024 | 11:48 AM
  #7  
raverx3m's Avatar
Thread Starter
Member
15 Year Member
 
Joined: May 2009
Posts: 209
Likes: 4
2011 c300 4matic
i checked everything visually and smell test. rear sam smells fresh looks uncorroded. front looks good as well

im assuming that the circuit 30g is the main issue causing all the other seemingly unrelated codes for random things around the car because all those features work fine i ran diagnostic and functional test on the heater flaps and they all move when tested by scanner. but they still throw codes

anyone can take a guess where else i should look?
Reply
Old Aug 31, 2024 | 11:54 AM
  #8  
trigital's Avatar
MBWorld Fanatic!
10 Year Member
Photogenic
Community Builder
Liked
 
Joined: Dec 2011
Posts: 1,692
Likes: 488
From: Spain UTC/GMT +2 hours
W213 All-terrain
All 30G circuits came from Right Fuse module ( the one with Red cover for jump start ). Sometimes this module become defective.
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-1

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-2

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-3

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-4

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-5

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-6

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-7

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-8

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
story-9

10 Most Reliable Mercedes-Benz Models You Can Buy Used

 Verdad Gallardo
Old Aug 31, 2024 | 02:46 PM
  #9  
JCM_MB's Avatar
MBWorld Fanatic!
Photogenic
Liked
Loved
Community Favorite
 
Joined: May 2021
Posts: 2,524
Likes: 2,041
From: US
2008 E350, 2012 ML350, 2014 E350, 2015 ML350
Originally Posted by trigital
All 30G circuits came from Right Fuse module ( the one with Red cover for jump start ). Sometimes this module become defective.
In particular if the car was jumped incorrectly, or sparked while connecting the cables.



Reply
Old Sep 1, 2024 | 03:43 PM
  #10  
CaliBenzDriver's Avatar
Out Of Control!!
Community Builder
Community Influencer
Liked
Community Favorite
 
Joined: Apr 2019
Posts: 11,921
Likes: 6,769
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Originally Posted by raverx3m
I work at a tint shop and yes the fuse box in mercedes has been always positioned right under water runoff.
they had this issue since late 90s.
and never fixed it.
where would i find reference to that circuit possibly?
google shows nothing for c300

Car shades load upon low voltage... (TimC300)

Is there a chance what you're dealing with is simply low voltage after keeping chassis awake too long without external power supply?
The fix to recharge main battery with a float charger.

Last edited by CaliBenzDriver; Sep 1, 2024 at 03:46 PM.
Reply
Old Sep 3, 2024 | 11:11 AM
  #11  
raverx3m's Avatar
Thread Starter
Member
15 Year Member
 
Joined: May 2009
Posts: 209
Likes: 4
2011 c300 4matic
looks like a waterline on circuit board in front fuse box module.
previous owner was an absolute idiot and didnt clip the fuse box cover back in so who knows how long the water been getting into it,

im getting codes but all the features work.
where in the front sam would the 30g circuit live? maybe its corroded from moisuture i want to check it out


the battery voltage is good. it has new ish battery
Reply
Old Sep 3, 2024 | 07:36 PM
  #12  
CaliBenzDriver's Avatar
Out Of Control!!
Community Builder
Community Influencer
Liked
Community Favorite
 
Joined: Apr 2019
Posts: 11,921
Likes: 6,769
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Originally Posted by raverx3m
looks like a waterline on circuit board in front fuse box module.
previous owner was an absolute idiot and didnt clip the fuse box cover back in so who knows how long the water been getting into it,

im getting codes but all the features work.
where in the front sam would the 30g circuit live? maybe its corroded from moisuture i want to check it out


the battery voltage is good. it has new ish battery
swampy front SAM.... the only thing to do is replace it. 30G circuit is routed all around it in unprotected PCB traces that develop short-circuit oxidation - - NO repair for Mercedes water damaged modules.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 06:51 AM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE