E-Class (W211) 2003-2009

EGR P0402

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Jun 21, 2012 | 05:09 PM
  #1  
Chip2011's Avatar
Thread Starter
Junior Member
 
Joined: Nov 2011
Posts: 15
Likes: 0
2008 E320 Bluetec
EGR P0402

Folks - I looking for a little help. I have been getting CEL for the EGR P0402 for excessive recir. I removed the EGR, EGR pipe and cleaned them with carb cleaner, and reset the code. Started the car and drove for about 20 miles, no CEL. On the very next start, CEL came on and it was the same code - P0402.

Question: which component sets this code? Is it the EGR or a sensor in the system? Is there a way to test the EGR? Is this code related to the EGR failing to close all the way? What is the component next the EGR that looks like a temp sensor? (screws into the same exhaust duct as the EGR)

The EGR is easy to replace but I don't know the system well enough to say that the problem is the EGR and not something else. I appreciate any help or advice you can give. I think this must be an easy problem to solve.

2008 E320 bluetec, 110,000 miles.
Reply
Old Jun 21, 2012 | 10:04 PM
  #2  
ozusa's Avatar
Member
 
Joined: Jan 2012
Posts: 244
Likes: 4
From: PA, USA
2004 E320 4matic Sedan
some comments

Originally Posted by Chip2011
Folks - I looking for a little help. I have been getting CEL for the EGR P0402 for excessive recir. I removed the EGR, EGR pipe and cleaned them with carb cleaner, and reset the code. Started the car and drove for about 20 miles, no CEL. On the very next start, CEL came on and it was the same code - P0402.

Question: which component sets this code? Is it the EGR or a sensor in the system? Is there a way to test the EGR? Is this code related to the EGR failing to close all the way? What is the component next the EGR that looks like a temp sensor? (screws into the same exhaust duct as the EGR)

The EGR is easy to replace but I don't know the system well enough to say that the problem is the EGR and not something else. I appreciate any help or advice you can give. I think this must be an easy problem to solve.

2008 E320 bluetec, 110,000 miles.
I am not familiar with the diesel systems, but according to what I've read about EGRs generally and P0402, is that the EGR valve is allowing too much exhaust gas to flow into the intake manifold. Given the text of the error message, that will come as no surprise to you.

Likely causes for that include a bad vacuum hose, if it is a vacuum-actuated EGR, or a dirty or worn EGR valve. For excessive flow to be the problem, I doubt that other passages in the system are blocked, because that would cause a lack of flow, not too much flow, I suppose.

Disassembling the EGR and cleaning it can help and check movement of the pintle and diaphragm, along with cleaning the port it fits into, but you shouldn't spray solvents on the diaphragm (so your carb cleaner may not necessarily have been the best thing to do.)

I can't say much more than that.

Haynes' "OBD-II & Electronic Engine Management Systems" book, ISBN 1 56392 612 1, is a good reference for more detail. Your local parts store probably has a copy for about US$20
Reply
Old Jun 21, 2012 | 10:53 PM
  #3  
Chip2011's Avatar
Thread Starter
Junior Member
 
Joined: Nov 2011
Posts: 15
Likes: 0
2008 E320 Bluetec
Does anyone know if the EGR valve is touching off the code or is there a sensor that trips it?

Can I test the proper operation of the EGR valve?
My system is electronic - no vacuum hoses.
Reply
Old May 31, 2013 | 04:17 PM
  #4  
Chip2011's Avatar
Thread Starter
Junior Member
 
Joined: Nov 2011
Posts: 15
Likes: 0
2008 E320 Bluetec
Follow up EGR

I wanted to post this as a follow up...My EGR has given up the ghost. Over a year ago, I took the EGR off and clean it and the tube, and tube connections and replaced with new gaskets. It worked like a champ until this month. Started getting CEL for EGR. I have the dealership check it for me and they found coded 2355-001 for EGR malfunction. They performed guided test through ads and found out EGR is defective and needs to be replaced.

The cleaning helped me get over a year out of it but now needs to be replaced. I'm going to replace it myself since it is pretty straight forward and on top of the engine.

2008 E320 Bluetec
130,000 miles - runs like a champ!
Reply
Old Jun 28, 2016 | 06:49 PM
  #5  
pinebaron's Avatar
MBWorld Fanatic!
15 Year Member
Photogenic
Photoriffic
Liked
 
Joined: May 2007
Posts: 1,252
Likes: 18
From: Blaine, WA
07 E320 Bluetec
Originally Posted by Chip2011
I wanted to post this as a follow up...My EGR has given up the ghost. Over a year ago, I took the EGR off and clean it and the tube, and tube connections and replaced with new gaskets. It worked like a champ until this month. Started getting CEL for EGR. I have the dealership check it for me and they found coded 2355-001 for EGR malfunction. They performed guided test through ads and found out EGR is defective and needs to be replaced.

The cleaning helped me get over a year out of it but now needs to be replaced. I'm going to replace it myself since it is pretty straight forward and on top of the engine.

2008 E320 Bluetec
130,000 miles - runs like a champ!
Did you get around to replacing the EGR valve and did it solve the code issue?
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 02:34 PM.

story-0
Six Gift Ideas Your AMG Loving Dad or Grad Will Cherish

Slideshow: Six gift ideas your AMG loving dad or grad will cherish.

By | 2026-06-03 17:26:18


VIEW MORE
story-1
7 Craziest Things AMG Gas Ever Built

Slideshow: Sometimes AMG builds fast sedans. Other times, it builds twin-turbo V12 land missiles and six-wheeled off-road monsters.

By Verdad Gallardo | 2026-05-26 17:59:58


VIEW MORE
story-2
New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

Slideshow: Mercedes-AMG's new electric GT 4-Door Coupe trades combustion for software, synthetic noise, and more than 1,100 horsepower.

By Verdad Gallardo | 2026-05-20 20:08:15


VIEW MORE
story-3
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-4
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-5
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-6
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-7
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-8
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-9
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