WIS help needed
Thread Starter
Senior Member
Joined: Dec 2006
Posts: 437
Likes: 168
All Cars Lost To Hurricane Isaac (W124 E420 revived - added 88 Allante 14 S550, 17 S63
WIS help needed
Reference: 2014 S550 - engine 278.929
I am away from my windows laptop with WIS, for the next few months, Can someone provide the engine ECU electrical diagram. It should show the two big connectors and all wiring interfaces. Not sure if that is just one diagram or two?
Using Xentry ( wink!), I have;
(1) a code P020113 : The Fuel Injector cylinder 1 has an electrical fault or an open circuit. There is an open circuit.
(2) code P030185 : cylinder 1 misfire. Signal above permissible limit value
(3) code P030085 : combustion misfire detected. Signal above permissible limit value
I have a misfire and would like to chase down the short.
cleared and reappeared immediately.... multiple times
I want to check the injector (and coil) wiring.
I am away from my windows laptop with WIS, for the next few months, Can someone provide the engine ECU electrical diagram. It should show the two big connectors and all wiring interfaces. Not sure if that is just one diagram or two?
Using Xentry ( wink!), I have;
(1) a code P020113 : The Fuel Injector cylinder 1 has an electrical fault or an open circuit. There is an open circuit.
(2) code P030185 : cylinder 1 misfire. Signal above permissible limit value
(3) code P030085 : combustion misfire detected. Signal above permissible limit value
I have a misfire and would like to chase down the short.
cleared and reappeared immediately.... multiple times
I want to check the injector (and coil) wiring.
MBWorld Fanatic!
Joined: Dec 2011
Posts: 1,768
Likes: 517
From: Spain UTC/GMT +2 hours
W213 All-terrain
Reference: 2014 S550 - engine 278.929
I am away from my windows laptop with WIS, for the next few months, Can someone provide the engine ECU electrical diagram. It should show the two big connectors and all wiring interfaces. Not sure if that is just one diagram or two?
Using Xentry ( wink!), I have;
(1) a code P020113 : The Fuel Injector cylinder 1 has an electrical fault or an open circuit. There is an open circuit.
(2) code P030185 : cylinder 1 misfire. Signal above permissible limit value
(3) code P030085 : combustion misfire detected. Signal above permissible limit value
I have a misfire and would like to chase down the short.
cleared and reappeared immediately.... multiple times
I want to check the injector (and coil) wiring.
I am away from my windows laptop with WIS, for the next few months, Can someone provide the engine ECU electrical diagram. It should show the two big connectors and all wiring interfaces. Not sure if that is just one diagram or two?
Using Xentry ( wink!), I have;
(1) a code P020113 : The Fuel Injector cylinder 1 has an electrical fault or an open circuit. There is an open circuit.
(2) code P030185 : cylinder 1 misfire. Signal above permissible limit value
(3) code P030085 : combustion misfire detected. Signal above permissible limit value
I have a misfire and would like to chase down the short.
cleared and reappeared immediately.... multiple times
I want to check the injector (and coil) wiring.
Also, Xentry is not a Fault Code reader, it's a very complex diagnosis system. Don't be afraid to use it,
Click on first Fault code,
1 - 2 new fields with sign+ become available with Data about when, how, time, km, etc
2 - after clicking the first Fault ( usually people starts with the one that they think is important), on the right button corner you will see "test" or "continue" where the pragmatic German thinking will start to teach you how things should be onto your step by step diagnosis
Good luck
Last edited by trigital; Jul 30, 2025 at 06:42 PM.
Thread Starter
Senior Member
Joined: Dec 2006
Posts: 437
Likes: 168
All Cars Lost To Hurricane Isaac (W124 E420 revived - added 88 Allante 14 S550, 17 S63
Holy Smokes..... I do a lot more than diagnostic , but wow, I never even glanced at the blue book. It's everything I need for this task....and will help me moving forward.... excellent and thank you
On right top corner in Xentry Engine ECU you can see a blue book, press on that icon, the book will open and a lot of goodies will be available.
Also, Xentry is not a Fault Code reader, it's a very complex diagnosis system. Don't be afraid to use it,
Click on first Fault code,
1 - 2 new fields with sign+ become available with Data about when, how, time, km, etc
2 - after clicking the first Fault ( usually people starts with the one that they think is important), on the right button corner you will see "test" or "continue" where the pragmatic German thinking will start to teach you how things should be onto your step by step diagnosis
Good luck
Also, Xentry is not a Fault Code reader, it's a very complex diagnosis system. Don't be afraid to use it,
Click on first Fault code,
1 - 2 new fields with sign+ become available with Data about when, how, time, km, etc
2 - after clicking the first Fault ( usually people starts with the one that they think is important), on the right button corner you will see "test" or "continue" where the pragmatic German thinking will start to teach you how things should be onto your step by step diagnosis
Good luck
Super Member
Joined: Jun 2025
Posts: 784
Likes: 251
From: USA
Check injector #1 wiring: Connector A black, 26-pin, pin 24 is signal;
Connector B brown, 26-pin, pin 24 is ground.
First test injector resistance should be 12-16Ω, then swap it with another cylinder. If misfire follows, replace injector. If not, check wiring for damage between ECU and injector. Clear codes to verify fix. Keep it simple 90% of the time it's just a bad injector.
Connector B brown, 26-pin, pin 24 is ground.
First test injector resistance should be 12-16Ω, then swap it with another cylinder. If misfire follows, replace injector. If not, check wiring for damage between ECU and injector. Clear codes to verify fix. Keep it simple 90% of the time it's just a bad injector.
Thread Starter
Senior Member
Joined: Dec 2006
Posts: 437
Likes: 168
All Cars Lost To Hurricane Isaac (W124 E420 revived - added 88 Allante 14 S550, 17 S63
I will do... thank you
Check injector #1 wiring: Connector A black, 26-pin, pin 24 is signal;
Connector B brown, 26-pin, pin 24 is ground.
First test injector resistance should be 12-16Ω, then swap it with another cylinder. If misfire follows, replace injector. If not, check wiring for damage between ECU and injector. Clear codes to verify fix. Keep it simple 90% of the time it's just a bad injector.
Connector B brown, 26-pin, pin 24 is ground.
First test injector resistance should be 12-16Ω, then swap it with another cylinder. If misfire follows, replace injector. If not, check wiring for damage between ECU and injector. Clear codes to verify fix. Keep it simple 90% of the time it's just a bad injector.
Thread Starter
Senior Member
Joined: Dec 2006
Posts: 437
Likes: 168
All Cars Lost To Hurricane Isaac (W124 E420 revived - added 88 Allante 14 S550, 17 S63
Got back to this finally,
I used the Xentry "blue book" and chased down any wiring shorts or grounding issues - all was fine.
It ended being an injector
Cleaned all of the injectors with a carb cleaner solution, including the tips, which had some build-up.
I re-sealed the rail, and replaced injector seals also, along with replacing the injector retaining clips ( MB has a kit)
The new injector had numbers (5 alphanumeric characters) which need to entered into the ECU. which is simple with Xentry
Ninja and I looked at the ECU for issues, and couldn't find any... he also pointed to the injectors
Purrs like a kitten
Thank you community, this fun diy saved me a ton
I used the Xentry "blue book" and chased down any wiring shorts or grounding issues - all was fine.
It ended being an injector
Cleaned all of the injectors with a carb cleaner solution, including the tips, which had some build-up.
I re-sealed the rail, and replaced injector seals also, along with replacing the injector retaining clips ( MB has a kit)
The new injector had numbers (5 alphanumeric characters) which need to entered into the ECU. which is simple with Xentry
Ninja and I looked at the ECU for issues, and couldn't find any... he also pointed to the injectors
Purrs like a kitten
Thank you community, this fun diy saved me a ton
Check injector #1 wiring: Connector A black, 26-pin, pin 24 is signal;
Connector B brown, 26-pin, pin 24 is ground.
First test injector resistance should be 12-16Ω, then swap it with another cylinder. If misfire follows, replace injector. If not, check wiring for damage between ECU and injector. Clear codes to verify fix. Keep it simple 90% of the time it's just a bad injector.
Connector B brown, 26-pin, pin 24 is ground.
First test injector resistance should be 12-16Ω, then swap it with another cylinder. If misfire follows, replace injector. If not, check wiring for damage between ECU and injector. Clear codes to verify fix. Keep it simple 90% of the time it's just a bad injector.
Last edited by kafklatsch; Aug 26, 2025 at 07:37 PM.
