C-Class (W203) 2001-2007, C160, C180, C200, C220, C230, C240, C270, C280, C300, C320, C230K, C350, Coupe

Looking for ECU wiring diagram for Check Engine light on 2006 C@30 (W203)

Old Sep 20, 2020 | 01:06 AM
  #1  
khalidnz's Avatar
Thread Starter
Newbie
 
Joined: Aug 2018
Posts: 6
Likes: 1
2007 CLS 350 Mercedes and 2006 C230
Smile Looking for ECU wiring diagram for Check Engine light on 2006 C@30 (W203)

Hi,
i own an 2006 C230 Mercedes (W203). I have an issue where my engine check warning light is not displaying. I found this out when I had an issue with my O2 sensor causing me issues which showed up on my scanner but there was not warning light showing. That was some time ago now and the car is running fine now (finger crossed I will have not more issues). However. I want to get the warning light displaying again, as this is a visual indication of any fault when they occur as a prompt to look further. At the moment i have to just check every couple of months with a small OBD2 scanner to see if there are any faults logged.
What i am looking for is a electronic schematic diagram for the ECU and in particular the Engine Check Warning light circuit. If I can get me hands on this i then do some electrical testes to make sure there are not broken or shorted wires (or bad connections in warning light circuit). Can anyone help with this request or information around the check engine like warning circuit and how it works on the this model Mercedes.

P.s. I am a automotive technician by trade so really just looking to get my hands on the schematics.

Regards
K
Reply
Old Sep 20, 2020 | 11:32 AM
  #2  
Russell Ormerod's Avatar
MBWorld Fanatic!
 
Joined: Jun 2011
Posts: 1,494
Likes: 131
From: Cape town
not a merc
Diagram will not help you. Signal is Via Can!
does the light come on when the ignition is switched on?
Reply
Old Sep 20, 2020 | 07:29 PM
  #3  
khalidnz's Avatar
Thread Starter
Newbie
 
Joined: Aug 2018
Posts: 6
Likes: 1
2007 CLS 350 Mercedes and 2006 C230
No light presents when ignition turned on or when fault registered. Rest of instrument panel working ok from what I can see. Hence why I was interested in getting schematic to look at to work through issue. I have tested the circuit board on the instrument panel and light is not blown. It seems to be a power issue with it bein powered on. Is there a circuit diagram i can get hold off for the warning light system from the can to the instrument panel? This what i need to be able to complete my testing rather than havin gto hunt for everything manually and try to reverse engineer things for testing.

Any help would be appreciated in regards to circuit digram.

Last edited by khalidnz; Sep 21, 2020 at 01:48 AM.
Reply
Old Sep 21, 2020 | 03:02 PM
  #4  
Russell Ormerod's Avatar
MBWorld Fanatic!
 
Joined: Jun 2011
Posts: 1,494
Likes: 131
From: Cape town
not a merc
There is no such circuit mate! Its an encoded message. No wiring diagram is going to help you. If your light is not working at ign on then you need to check the coding of the instrument cluster. Its probably been disabled in software. To make it work you need star diagnose. No cheap OBD tool will help you either.
Reply

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

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 07:56 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