DIY article: W210 DIESEL EGR-disable Mod!
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Super Member
Joined: Jun 2006
Posts: 525
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From: the Netherlands
'01 W210 E320 CDI
DIY article: W210 DIESEL EGR-disable Mod!
Disclaimer: READ people! This article is a compilation/summary of posts on UK-based MB owners forums. All credit goes to 'Dieselman' and 'Oygle' there! Please DO NOT PM me about if this works on car 'X' or petrol engines. I simply do not know!!! I did the below mod to my own car and it works. I DO NOT want to invest any more time and effort in it so please work with the info below. You do this mod at YOUR OWN RISK!!! Neither me, MBWorld.org, or anyone other than YOURSELF can be held responsible for seriously damaging the electronic systems in your car if you don't know what you're doing!!! And before replying, PMing: please READ...people!
__________
Mod to disable the EGR on DIESEL engines.
In general it's felt that having the EGR (ExhaustGas Recirculation) system on DIESEL engines is good for reducing the NOX output but bad in all other respects. It reduces economy, creates more smoke, increases problems and maintenance requirements due to clogging the intake and can reduce overall engine life. As a result of wanting greater economy many owners want to stop the exhaust gas being recirculated. The problem with doing this on a modern engine is that the EGR valve operation is monitored by the Engine Computer (ECU). The only way to disable the EGR and not trip a fault code and limp home mode is to fool the ECU into thinking the EGR is still working.
This mod works on earlier TurboDiesel and CDI cars with a vacuum-controlled EGR valve. Check to see if your EGR-valve ONLY has a vacuum-hose connected to it’s BODY.
(If the actual EGR-valve BODY has an electrical connection this mod won’t work...)
Skills involved are sorting out wires, using a multimeter and handling a soldering iron...
Pros:
- Less sooth output
- Less CO2 output
- No more ‘sooth/grease/gunk’- buildup in the inletmanifold (choking the engine)
- Smoother and quieter running engine
- Fuel economy improves around 2%
Cons:
- NOX output increases
- On CDI engines, warmup time increases. CDI’s have an exhaustgas/coolant-heatexchanger shunted through EGR operation. Take it easy the first few miles (like you should anyways!)
How does it work?
The Engine Computer (ECU) measures intake airflow using the Mass Air Flow sensor (MAF). This MAF is situated in the airstream right behind the airfilter box. When the EGR-valve is opened, a portion of the exhaust gasses are sucked directly into the inlet manifold (further downstream) so the ECU measures a slight drop in airflow through the air filter box. (the MAF puts out a slightly lower Voltage signal)
When removing the vacuum-hose for EGR-operation, or blocking off the EGR valve, the ECU does not measure the slight drop of airflow on the MAF when it operates the EGR and eventually throws an error code and puts the car into limp-home-mode! The ECU will also limp the car when it does not ‘see’ the EGR transducer. (This tranducer controls the vacuum to operate the actual EGR-valve)
The Modification:
A small circuit (consisting of two resistors and a diode) is hooked-up to the wiring harness going to the ECU. One 1kΩ resistor acts as (the load of) the EGR transducer. Another 470Ω resistor in series with a 1N4004-diode utilizes the control signal for EGR operation to pull the Voltage drop the ECU expects to see on the MAF-signal. That’s all! The ECU is fooled, and the engine still gets the same amount of airflow but it’s all clean air coming through the inlet, getting full boost!
The EGR-transducer can now simply be unplugged. This causes the EGR-valve to stay closed at all time. That’s it! No clipping of wires and everything still looks original under the hood. For emissions testing, if needed you can simply connect the EGR-transducer and unplug it again when passed!!!
Making the circuit:
1/4 watt resistors are fine as there is no current, just signal voltage.
First identify your components. L-R = diode, 470 ohm and 1000 ohm resistors.
Solder the 470 ohm resistor to the tail of the diode. Note the silver band on the diode shows which is the + positive blocking.
Add the 1k ohm resistor to the other end of the diode and add appropriate wire then clip off any stray tails.
Fit heatshrink tubing to the bare sections.
And then tape over with material tape for protection to complete.
(The Red wire is +12v, Yellow is MAF, Green is EGR transducer signal.)
Hooking it up to the car:
Please - everyone doing this Mod. DON'T take wire colours for granted. All models are different.
Locate the appropriate wire at the MAF using a simple voltage meter. Look for the wire at the maf that indicates a Voltage change in the range of 2 to 4 volts approx. when the engine is Revved. When you have located the wire, note the colours and find the same wire near the ecu. The 12 Volt power source at the ecu of the 300TD is easy to find, once again with a meter, and the wire at the EGR transducer is also simple to locate, once again note the colour at the unit and find it again near the ecu. This is the only failsafe procedure!!!
Below are the known connections for W210 300 TurboDiesel and W210 270CDI, W210 320CDI and W163 ML270 CDI.
EGR transducer negative side:
300 TD: Pin 35 (grey-green wire)
CDI: Plug 3, Pin 50 (grey-black wire)
EGR transducer positive side:
300 TD: Any pin/wire that has switched +12V
CDI: Plug 3, Pin 37 (grey-red wire)
MAF signal:
300 TD: Pin 21 (yellow-white wire)
CDI: Plug 2, Pin 24 (yellow-white wire)
Inside the ECU box:
Hook up the circuit inside this box. It will be insulated and safely dry there!
Good luck!
A next project will be taking off my inlet manifold and clean out all the gunk that's probably inside. Below a pic of the inlet channels on a OM613 320CDI after 300k KM's...
__________
Mod to disable the EGR on DIESEL engines.
In general it's felt that having the EGR (ExhaustGas Recirculation) system on DIESEL engines is good for reducing the NOX output but bad in all other respects. It reduces economy, creates more smoke, increases problems and maintenance requirements due to clogging the intake and can reduce overall engine life. As a result of wanting greater economy many owners want to stop the exhaust gas being recirculated. The problem with doing this on a modern engine is that the EGR valve operation is monitored by the Engine Computer (ECU). The only way to disable the EGR and not trip a fault code and limp home mode is to fool the ECU into thinking the EGR is still working.
This mod works on earlier TurboDiesel and CDI cars with a vacuum-controlled EGR valve. Check to see if your EGR-valve ONLY has a vacuum-hose connected to it’s BODY.
(If the actual EGR-valve BODY has an electrical connection this mod won’t work...)
Skills involved are sorting out wires, using a multimeter and handling a soldering iron...
Pros:
- Less sooth output
- Less CO2 output
- No more ‘sooth/grease/gunk’- buildup in the inletmanifold (choking the engine)
- Smoother and quieter running engine
- Fuel economy improves around 2%
Cons:
- NOX output increases
- On CDI engines, warmup time increases. CDI’s have an exhaustgas/coolant-heatexchanger shunted through EGR operation. Take it easy the first few miles (like you should anyways!)
How does it work?
The Engine Computer (ECU) measures intake airflow using the Mass Air Flow sensor (MAF). This MAF is situated in the airstream right behind the airfilter box. When the EGR-valve is opened, a portion of the exhaust gasses are sucked directly into the inlet manifold (further downstream) so the ECU measures a slight drop in airflow through the air filter box. (the MAF puts out a slightly lower Voltage signal)
When removing the vacuum-hose for EGR-operation, or blocking off the EGR valve, the ECU does not measure the slight drop of airflow on the MAF when it operates the EGR and eventually throws an error code and puts the car into limp-home-mode! The ECU will also limp the car when it does not ‘see’ the EGR transducer. (This tranducer controls the vacuum to operate the actual EGR-valve)
The Modification:
A small circuit (consisting of two resistors and a diode) is hooked-up to the wiring harness going to the ECU. One 1kΩ resistor acts as (the load of) the EGR transducer. Another 470Ω resistor in series with a 1N4004-diode utilizes the control signal for EGR operation to pull the Voltage drop the ECU expects to see on the MAF-signal. That’s all! The ECU is fooled, and the engine still gets the same amount of airflow but it’s all clean air coming through the inlet, getting full boost!
The EGR-transducer can now simply be unplugged. This causes the EGR-valve to stay closed at all time. That’s it! No clipping of wires and everything still looks original under the hood. For emissions testing, if needed you can simply connect the EGR-transducer and unplug it again when passed!!!
Making the circuit:
1/4 watt resistors are fine as there is no current, just signal voltage.
First identify your components. L-R = diode, 470 ohm and 1000 ohm resistors.
Solder the 470 ohm resistor to the tail of the diode. Note the silver band on the diode shows which is the + positive blocking.
Add the 1k ohm resistor to the other end of the diode and add appropriate wire then clip off any stray tails.
Fit heatshrink tubing to the bare sections.
And then tape over with material tape for protection to complete.
(The Red wire is +12v, Yellow is MAF, Green is EGR transducer signal.)
Hooking it up to the car:
Please - everyone doing this Mod. DON'T take wire colours for granted. All models are different.
Locate the appropriate wire at the MAF using a simple voltage meter. Look for the wire at the maf that indicates a Voltage change in the range of 2 to 4 volts approx. when the engine is Revved. When you have located the wire, note the colours and find the same wire near the ecu. The 12 Volt power source at the ecu of the 300TD is easy to find, once again with a meter, and the wire at the EGR transducer is also simple to locate, once again note the colour at the unit and find it again near the ecu. This is the only failsafe procedure!!!
Below are the known connections for W210 300 TurboDiesel and W210 270CDI, W210 320CDI and W163 ML270 CDI.
EGR transducer negative side:
300 TD: Pin 35 (grey-green wire)
CDI: Plug 3, Pin 50 (grey-black wire)
EGR transducer positive side:
300 TD: Any pin/wire that has switched +12V
CDI: Plug 3, Pin 37 (grey-red wire)
MAF signal:
300 TD: Pin 21 (yellow-white wire)
CDI: Plug 2, Pin 24 (yellow-white wire)
Inside the ECU box:
Hook up the circuit inside this box. It will be insulated and safely dry there!
Good luck!
A next project will be taking off my inlet manifold and clean out all the gunk that's probably inside. Below a pic of the inlet channels on a OM613 320CDI after 300k KM's...
Newbie
Joined: Jul 2012
Posts: 2
Likes: 0
From: Sussex UK
W210 E320CDI AvG estate
All made up and installed, engine sweet and no error messages
Only differences on my car was EGR pos is red/black, neg is grey/black
MAF signal yellow/white but plug 4 not 2 on my car.
Thanks for the heads up on this one, looking forward to drive to work tomorrow!!
Only differences on my car was EGR pos is red/black, neg is grey/black
MAF signal yellow/white but plug 4 not 2 on my car.
Thanks for the heads up on this one, looking forward to drive to work tomorrow!!
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MBWorld Fanatic!
Joined: May 2005
Posts: 2,825
Likes: 3
From: New Jersey
things with and without wheels
The op listed the 2 resistors and a diode that you need as well as a diagram.
If you have any friends that play with electronics show them the diagram and they will know what to do.
Newbie
Joined: Sep 2012
Posts: 5
Likes: 0
From: Denmark copenhagen
w210 320 cdi 2002
hi mate, ye i know how to do the job when i have the parts but there soooo many different diode types and the same with transistors
Junior Member
Joined: May 2011
Posts: 53
Likes: 0
From: England, UK
W210 2002 E320 CDi Avantgarde
Some pics here: http://forums.mercedesclub.org.uk/sh...ad.php?t=68928
Newbie
Joined: Oct 2013
Posts: 2
Likes: 0
clk 270 cdi c209
Hiya all -i'm newbie on this forum, but hope to contribute wherever I can.
I've been following this thread and others for a while and took the plunge. I've made up my shunt from a few bits in my toolbox and began tracing wiring on my 2005 CLK 270CDi (C209)
The EGR wires are quite straight forward - and present themselves as a twisted pait in ECU enclosure.
However the MAF is a tad confusing.
I believe the signal wire is always on the terminal 5 of MAF plug, and should show a swing of 2-4Vdc when engine rev'd. However when I've tested my term 5 output ( connect to MAF and probed through insulation) _ achieving a 0.5Vdc swing from 0.5 - 1.0 V - is this correct?
More confusing still - the wire on MAF plug is BR/WHT yet when belled back to ECU it has swapped colour to YL/WHT - (pin 24 on plug 4).
Is it normal for wiring to change colour code mid run?
any help greatly appreciated
Alistair
I've been following this thread and others for a while and took the plunge. I've made up my shunt from a few bits in my toolbox and began tracing wiring on my 2005 CLK 270CDi (C209)
The EGR wires are quite straight forward - and present themselves as a twisted pait in ECU enclosure.
However the MAF is a tad confusing.
I believe the signal wire is always on the terminal 5 of MAF plug, and should show a swing of 2-4Vdc when engine rev'd. However when I've tested my term 5 output ( connect to MAF and probed through insulation) _ achieving a 0.5Vdc swing from 0.5 - 1.0 V - is this correct?
More confusing still - the wire on MAF plug is BR/WHT yet when belled back to ECU it has swapped colour to YL/WHT - (pin 24 on plug 4).
Is it normal for wiring to change colour code mid run?
any help greatly appreciated
Alistair
Junior Member
Joined: Jan 2010
Posts: 20
Likes: 0
From: Chile
1993 300D turbo
EGR disable well done in diesel engines
Disclaimer: READ people! This article is a compilation/summary of posts on UK-based MB owners forums. All credit goes to 'Dieselman' and 'Oygle' there! Please DO NOT PM me about if this works on car 'X' or petrol engines. I simply do not know!!! I did the below mod to my own car and it works. I DO NOT want to invest any more time and effort in it so please work with the info below. You do this mod at YOUR OWN RISK!!! Neither me, MBWorld.org, or anyone other than YOURSELF can be held responsible for seriously damaging the electronic systems in your car if you don't know what you're doing!!! And before replying, PMing: please READ...people!
__________
Mod to disable the EGR on DIESEL engines.
In general it's felt that having the EGR (ExhaustGas Recirculation) system on DIESEL engines is good for reducing the NOX output but bad in all other respects. It reduces economy, creates more smoke, increases problems and maintenance requirements due to clogging the intake and can reduce overall engine life. As a result of wanting greater economy many owners want to stop the exhaust gas being recirculated. The problem with doing this on a modern engine is that the EGR valve operation is monitored by the Engine Computer (ECU). The only way to disable the EGR and not trip a fault code and limp home mode is to fool the ECU into thinking the EGR is still working.
This mod works on earlier TurboDiesel and CDI cars with a vacuum-controlled EGR valve. Check to see if your EGR-valve ONLY has a vacuum-hose connected to it’s BODY.
(If the actual EGR-valve BODY has an electrical connection this mod won’t work...)
Skills involved are sorting out wires, using a multimeter and handling a soldering iron...
Pros:
- Less sooth output
- Less CO2 output
- No more ‘sooth/grease/gunk’- buildup in the inletmanifold (choking the engine)
- Smoother and quieter running engine
- Fuel economy improves around 2%
Cons:
- NOX output increases
- On CDI engines, warmup time increases. CDI’s have an exhaustgas/coolant-heatexchanger shunted through EGR operation. Take it easy the first few miles (like you should anyways!)
How does it work?
The Engine Computer (ECU) measures intake airflow using the Mass Air Flow sensor (MAF). This MAF is situated in the airstream right behind the airfilter box. When the EGR-valve is opened, a portion of the exhaust gasses are sucked directly into the inlet manifold (further downstream) so the ECU measures a slight drop in airflow through the air filter box. (the MAF puts out a slightly lower Voltage signal)
When removing the vacuum-hose for EGR-operation, or blocking off the EGR valve, the ECU does not measure the slight drop of airflow on the MAF when it operates the EGR and eventually throws an error code and puts the car into limp-home-mode! The ECU will also limp the car when it does not ‘see’ the EGR transducer. (This tranducer controls the vacuum to operate the actual EGR-valve)
The Modification:
A small circuit (consisting of two resistors and a diode) is hooked-up to the wiring harness going to the ECU. One 1kΩ resistor acts as (the load of) the EGR transducer. Another 470Ω resistor in series with a 1N4004-diode utilizes the control signal for EGR operation to pull the Voltage drop the ECU expects to see on the MAF-signal. That’s all! The ECU is fooled, and the engine still gets the same amount of airflow but it’s all clean air coming through the inlet, getting full boost!
The EGR-transducer can now simply be unplugged. This causes the EGR-valve to stay closed at all time. That’s it! No clipping of wires and everything still looks original under the hood. For emissions testing, if needed you can simply connect the EGR-transducer and unplug it again when passed!!!
Making the circuit:
1/4 watt resistors are fine as there is no current, just signal voltage.
First identify your components. L-R = diode, 470 ohm and 1000 ohm resistors.
Solder the 470 ohm resistor to the tail of the diode. Note the silver band on the diode shows which is the + positive blocking.
Add the 1k ohm resistor to the other end of the diode and add appropriate wire then clip off any stray tails.
Fit heatshrink tubing to the bare sections.
And then tape over with material tape for protection to complete.
(The Red wire is +12v, Yellow is MAF, Green is EGR transducer signal.)
Hooking it up to the car:
Please - everyone doing this Mod. DON'T take wire colours for granted. All models are different.
Locate the appropriate wire at the MAF using a simple voltage meter. Look for the wire at the maf that indicates a Voltage change in the range of 2 to 4 volts approx. when the engine is Revved. When you have located the wire, note the colours and find the same wire near the ecu. The 12 Volt power source at the ecu of the 300TD is easy to find, once again with a meter, and the wire at the EGR transducer is also simple to locate, once again note the colour at the unit and find it again near the ecu. This is the only failsafe procedure!!!
Below are the known connections for W210 300 TurboDiesel and W210 270CDI, W210 320CDI and W163 ML270 CDI.
EGR transducer negative side:
300 TD: Pin 35 (grey-green wire)
CDI: Plug 3, Pin 50 (grey-black wire)
EGR transducer positive side:
300 TD: Any pin/wire that has switched +12V
CDI: Plug 3, Pin 37 (grey-red wire)
MAF signal:
300 TD: Pin 21 (yellow-white wire)
CDI: Plug 2, Pin 24 (yellow-white wire)
Inside the ECU box:
Hook up the circuit inside this box. It will be insulated and safely dry there!
Good luck!
A next project will be taking off my inlet manifold and clean out all the gunk that's probably inside. Below a pic of the inlet channels on a OM613 320CDI after 300k KM's...
__________
Mod to disable the EGR on DIESEL engines.
In general it's felt that having the EGR (ExhaustGas Recirculation) system on DIESEL engines is good for reducing the NOX output but bad in all other respects. It reduces economy, creates more smoke, increases problems and maintenance requirements due to clogging the intake and can reduce overall engine life. As a result of wanting greater economy many owners want to stop the exhaust gas being recirculated. The problem with doing this on a modern engine is that the EGR valve operation is monitored by the Engine Computer (ECU). The only way to disable the EGR and not trip a fault code and limp home mode is to fool the ECU into thinking the EGR is still working.
This mod works on earlier TurboDiesel and CDI cars with a vacuum-controlled EGR valve. Check to see if your EGR-valve ONLY has a vacuum-hose connected to it’s BODY.
(If the actual EGR-valve BODY has an electrical connection this mod won’t work...)
Skills involved are sorting out wires, using a multimeter and handling a soldering iron...
Pros:
- Less sooth output
- Less CO2 output
- No more ‘sooth/grease/gunk’- buildup in the inletmanifold (choking the engine)
- Smoother and quieter running engine
- Fuel economy improves around 2%
Cons:
- NOX output increases
- On CDI engines, warmup time increases. CDI’s have an exhaustgas/coolant-heatexchanger shunted through EGR operation. Take it easy the first few miles (like you should anyways!)
How does it work?
The Engine Computer (ECU) measures intake airflow using the Mass Air Flow sensor (MAF). This MAF is situated in the airstream right behind the airfilter box. When the EGR-valve is opened, a portion of the exhaust gasses are sucked directly into the inlet manifold (further downstream) so the ECU measures a slight drop in airflow through the air filter box. (the MAF puts out a slightly lower Voltage signal)
When removing the vacuum-hose for EGR-operation, or blocking off the EGR valve, the ECU does not measure the slight drop of airflow on the MAF when it operates the EGR and eventually throws an error code and puts the car into limp-home-mode! The ECU will also limp the car when it does not ‘see’ the EGR transducer. (This tranducer controls the vacuum to operate the actual EGR-valve)
The Modification:
A small circuit (consisting of two resistors and a diode) is hooked-up to the wiring harness going to the ECU. One 1kΩ resistor acts as (the load of) the EGR transducer. Another 470Ω resistor in series with a 1N4004-diode utilizes the control signal for EGR operation to pull the Voltage drop the ECU expects to see on the MAF-signal. That’s all! The ECU is fooled, and the engine still gets the same amount of airflow but it’s all clean air coming through the inlet, getting full boost!
The EGR-transducer can now simply be unplugged. This causes the EGR-valve to stay closed at all time. That’s it! No clipping of wires and everything still looks original under the hood. For emissions testing, if needed you can simply connect the EGR-transducer and unplug it again when passed!!!
Making the circuit:
1/4 watt resistors are fine as there is no current, just signal voltage.
First identify your components. L-R = diode, 470 ohm and 1000 ohm resistors.
Solder the 470 ohm resistor to the tail of the diode. Note the silver band on the diode shows which is the + positive blocking.
Add the 1k ohm resistor to the other end of the diode and add appropriate wire then clip off any stray tails.
Fit heatshrink tubing to the bare sections.
And then tape over with material tape for protection to complete.
(The Red wire is +12v, Yellow is MAF, Green is EGR transducer signal.)
Hooking it up to the car:
Please - everyone doing this Mod. DON'T take wire colours for granted. All models are different.
Locate the appropriate wire at the MAF using a simple voltage meter. Look for the wire at the maf that indicates a Voltage change in the range of 2 to 4 volts approx. when the engine is Revved. When you have located the wire, note the colours and find the same wire near the ecu. The 12 Volt power source at the ecu of the 300TD is easy to find, once again with a meter, and the wire at the EGR transducer is also simple to locate, once again note the colour at the unit and find it again near the ecu. This is the only failsafe procedure!!!
Below are the known connections for W210 300 TurboDiesel and W210 270CDI, W210 320CDI and W163 ML270 CDI.
EGR transducer negative side:
300 TD: Pin 35 (grey-green wire)
CDI: Plug 3, Pin 50 (grey-black wire)
EGR transducer positive side:
300 TD: Any pin/wire that has switched +12V
CDI: Plug 3, Pin 37 (grey-red wire)
MAF signal:
300 TD: Pin 21 (yellow-white wire)
CDI: Plug 2, Pin 24 (yellow-white wire)
Inside the ECU box:
Hook up the circuit inside this box. It will be insulated and safely dry there!
Good luck!
A next project will be taking off my inlet manifold and clean out all the gunk that's probably inside. Below a pic of the inlet channels on a OM613 320CDI after 300k KM's...
OldBeaver
Newbie
Joined: Apr 2015
Posts: 2
Likes: 0
ml270
Junior Member
Joined: Jan 2010
Posts: 20
Likes: 0
From: Chile
1993 300D turbo
EGR disable on diesels
I am interested on getting the mod, but I need to see the image to know if it will work on my OM603 turbo.Oldbeaver
