2004 S600: Cyl 1-6 Misfire after 3 seconds of Starting Engine
Thread Starter
Senior Member
Joined: Dec 2002
Posts: 348
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From: Florida
W124, W126, W140, W220, W222, R129
2004 S600: Cyl 1-6 Misfire after 3 seconds of Starting Engine
Hey guys. I'm facing an unusual problem. I bought a 2004 S600 with a misfire on 1-6. I figure coil pack, vt, etc. The regular, why walk away from it. It's a fun project.
Ordered my CP (from Clark) and bought a new VT (reman) from MB.
Installed all today and still the same miss. Cleared the codes, still the same thing. Starts up fine, after 3-4 seconds; CEL & misfire 1-6.
I did notice a tube with a vacuum hose coming off the right IC that isn't attached to anything. Could this be the cause, or am I chasing the wrong thread?
I haven't looked, but does SDS have an area to testO2 sensors & MAP sensors?
All help is truly appreciated!
Ordered my CP (from Clark) and bought a new VT (reman) from MB.
Installed all today and still the same miss. Cleared the codes, still the same thing. Starts up fine, after 3-4 seconds; CEL & misfire 1-6.
I did notice a tube with a vacuum hose coming off the right IC that isn't attached to anything. Could this be the cause, or am I chasing the wrong thread?
I haven't looked, but does SDS have an area to testO2 sensors & MAP sensors?
All help is truly appreciated!
Thread Starter
Senior Member
Joined: Dec 2002
Posts: 348
Likes: 20
From: Florida
W124, W126, W140, W220, W222, R129
I also plan to change plugs at the same time.
How can I tell if O2 sensors are bad?
Super Member
Joined: Sep 2012
Posts: 690
Likes: 76
From: Montreal, Quebec
2009 E350 4M Avantgarde;mistress 2002 S600; wife 2014 C300 4M
You need to approach this systematically:
1) You need to read the misfire code with SDS (nothing else will do it). If it shows Misfire 1 - 6 TWC DAMAGE, it means the ECU shuts that bank down to protect the cats.
2) You need somebody with the necessary skill to read the O2 sensors on that side "live" with SDS
3) if the O2 sensors are "off", you can change them, but sometimes you can you need to check the cats, and then you can shim the sensors "out" the improve the reading. (there are also shims available with their own catalyst values.) NOT from MB!
4) The transformer you installed MUST match the part number for your engine model; if not will not work right.
Good luck!
BTW: The above codes always clear on next start, and then reappear.
1) You need to read the misfire code with SDS (nothing else will do it). If it shows Misfire 1 - 6 TWC DAMAGE, it means the ECU shuts that bank down to protect the cats.
2) You need somebody with the necessary skill to read the O2 sensors on that side "live" with SDS
3) if the O2 sensors are "off", you can change them, but sometimes you can you need to check the cats, and then you can shim the sensors "out" the improve the reading. (there are also shims available with their own catalyst values.) NOT from MB!
4) The transformer you installed MUST match the part number for your engine model; if not will not work right.
Good luck!
BTW: The above codes always clear on next start, and then reappear.
Thread Starter
Senior Member
Joined: Dec 2002
Posts: 348
Likes: 20
From: Florida
W124, W126, W140, W220, W222, R129
Misfire Listing
The red line is right O2 sensor
Upstream Engine On
Upstream Engine Off
Downstream Engine On
Downstream Engine Off
These O2 numbers look normal?
Car starts up fine, but then gets CEL and shuts off right bank after 3-4 seconds.
Fixed the vacuum leaks and got new spark plugs this morning before these pictures. So its safe to say those two items can be ruled out, on top of the new coilpack and VT.
Super Member
Joined: Sep 2012
Posts: 690
Likes: 76
From: Montreal, Quebec
2009 E350 4M Avantgarde;mistress 2002 S600; wife 2014 C300 4M
The answer is in your first image: The ECU is shutting down that bank to protect the cats due to O2 values.
Get some good Indie help; don't throw parts at it.
Good luck!
BTW: 2.7.1 is for M137; you should be 2.8.1 for your engine model M275 (I believe)
Get some good Indie help; don't throw parts at it.
Good luck!
BTW: 2.7.1 is for M137; you should be 2.8.1 for your engine model M275 (I believe)
Last edited by kraut56; Nov 3, 2021 at 08:32 AM.
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Thread Starter
Senior Member
Joined: Dec 2002
Posts: 348
Likes: 20
From: Florida
W124, W126, W140, W220, W222, R129
I was thinking of replacing O2 and then looking at the CATS for possibly being damaged or plugged.
I want to do as much as I can before sending it to the Independent.
Based on the pictures, do you think its upstream or downstream O2 causing issues; or both?
Thanks in advance!
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Thread Starter
Senior Member
Joined: Dec 2002
Posts: 348
Likes: 20
From: Florida
W124, W126, W140, W220, W222, R129
I was told that it could be a bad ECU. I am trying to figure out how to check an ECU.
Thread Starter
Senior Member
Joined: Dec 2002
Posts: 348
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From: Florida
W124, W126, W140, W220, W222, R129
Super Member
Joined: May 2021
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From: Netherlands
CL 600 '00 5.8L V12
Why did they think it was a bad ECU? You could try to reset the ECU through DAS/Xentry
Also, https://mbworld.org/forums/w211-amg/...ispreloading=1
This sometimes seems to help
Also, https://mbworld.org/forums/w211-amg/...ispreloading=1
This sometimes seems to help
Newbie
Joined: Feb 2021
Posts: 4
Likes: 0
2009 S63 AMG
Issue Solved?
Reviving this thread because I am coming across the exact same issue with my CL65. Did it end up being the ECU? I've replaced O2 sensors and other bank specific sensors, ignition is all in good order, so I am stumped! What ended up being the problem?
Thanks!
Thanks!
