CDI3 EGR bypass mod

[AdamG]

This may be irrelevant but does your car have a diesel particulate filter fitted?

I ask as the ecu may be detecting an error via the oxygen sensors in the exhaust.

Adam

 

[Alex Crow]

OK, next test will be to disconnect the transistor from the connection to the R3 and diode.
In other words, check the R3 and diode combination is working to drag down the MAF sensor voltage - it should.

We can assume that R1 is doing its job because you do not have an 'actuator open circuit' or 'actuator signals fault through ground keying' fault code.

What colour wires have you isolated for PWM, 12v and 0v at the EGR valve?

Next check the continuity at the tranny:
Emitter = 643 ohms to ground/0v line
Collector = 0 ohms to the 12v line
Base = 22,000 ohms to PWM line and 24,700 ohms to 12v line

Also check for 12v at the 12v and 0v at the 0v!!

To familiarise yourself with the tranny connections look here.... http://www.markallen.com/teaching/ucsd/147a/lectures/lecture3/10.php
And here... http://www.kpsec.freeuk.com/trancirc.htm
And below

 

[Homebrewer]

This may be irrelevant but does your car have a diesel particulate filter fitted?

I ask as the ecu may be detecting an error via the oxygen sensors in the exhaust.

Adam

Yes, it does have a particle trap filter but I do not recall seeing an oxygen sensor attached to it. Will check that out though. Thanks for the input.

steve

 

[Homebrewer]

OK, next test will be to disconnect the transistor from the connection to the R3 and diode.
In other words, check the R3 and diode combination is working to drag down the MAF sensor voltage - it should.

We can assume that R1 is doing its job because you do not have an 'actuator open circuit' or 'actuator signals fault through ground keying' fault code.

What colour wires have you isolated for PWM, 12v and 0v at the EGR valve?

Next check the continuity at the tranny:
Emitter = 643 ohms to ground/0v line
Collector = 0 ohms to the 12v line
Base = 22,000 ohms to PWM line and 24,700 ohms to 12v line

Also check for 12v at the 12v and 0v at the 0v!!

To familiarise yourself with the tranny connections look here.... http://www.markallen.com/teaching/ucsd/147a/lectures/lecture3/10.php
And here... http://www.kpsec.freeuk.com/trancirc.htm
And below

Alex,
Hope to get back on this project the first patt of next week. Will let you know findings then. Thanks!!

steve

 

[Homebrewer]

Alex,
FINALLY SUCCESS! Your last bit of troubleshooting was priceless. I will go over all the stupid mistakes I made in hopes that it will help others who build this mod.

1.As I reported earlier, I had installed the transistor backwards. The drawings that I looked at on line were somewhat confusing and the transistors I ordered had no identifying marks. Lesson learned; make absolutely sure you have correctly identified the emitter, collector, and base.
2.Don’t trust resistor markings! I was using a 560 and an 82 ohm in series to get the 643 ohms needed for R3. The resistors were correctly color coded, but, the actual resistance of the 560 ohm was .550 MEGA ohms. I had checked this resistor twice with a meter but because I was seeing 550 on the ohm meter, I failed to notice the”. “ And the small m. I could blame my old eyes but that would be a poor excuse.

It is a testament to the beauty of your design that I did not fry the ecu. I now have plenty of power, no smoke, and do not have to spend $900 at the dealer to have a new egr valve installed and programmed. I will report back on fuel economy once I have some miles on the mod. You are a saint and if I lived in your area, you would be my repair shop of choice.

 

[Alex Crow]

Alex,
FINALLY SUCCESS! Your last bit of troubleshooting was priceless. I will go over all the stupid mistakes I made in hopes that it will help others who build this mod.

1.As I reported earlier, I had installed the transistor backwards. The drawings that I looked at on line were somewhat confusing and the transistors I ordered had no identifying marks. Lesson learned; make absolutely sure you have correctly identified the emitter, collector, and base.
2.Don’t trust resistor markings! I was using a 560 and an 82 ohm in series to get the 643 ohms needed for R3. The resistors were correctly color coded, but, the actual resistance of the 560 ohm was .550 MEGA ohms. I had checked this resistor twice with a meter but because I was seeing 550 on the ohm meter, I failed to notice the”. “ And the small m. I could blame my old eyes but that would be a poor excuse.

It is a testament to the beauty of your design that I did not fry the ecu. I now have plenty of power, no smoke, and do not have to spend $900 at the dealer to have a new egr valve installed and programmed. I will report back on fuel economy once I have some miles on the mod. You are a saint and if I lived in your area, you would be my repair shop of choice.

This post has made my day!

So glad it is now working for you homebrewer!

I look forward to hearing more, over time, about how you get on with it.

Alex

 

[tawfeeq]

any updates on the mod am planning to do it on my car and i really appriciate your efforts guys it was really informative

 

[tawfeeq]

oh alex would please let me know what shoud the voltage originally be on the MAF would help me greatly in finding the right wire wether the black or red one

 

[Alex Crow]

Voltage should be around 1.8-2v at idle.
I am thinking pin 5 at the MAF sensor, probably red/blue or just blue wire.

 

[Alex Crow]

I note that EGR emulators are now available on ebay!

Only £100 too.....

 

[maipac]

Hi all from Spain, congratulations on this great forum.

Halex Crow, thanks for giving this circuit to simulate EGR valve.
I built this circuit and added a disconnect switch between 12V / MAF and PWM.
I go into emergency mode, can be at the switch that causes this?
Engine symbol light was kindled. Hare no switch test to see what happens. Does this engine light goes away by itself or star diagnosis necessary?
Thank you.

 

[maipac]

Hi all from Spain, congratulations on this great forum.

Halex Crow, thanks for giving this circuit to simulate EGR valve.
I built this circuit and added a disconnect switch between 12V / MAF and PWM.
I go into emergency mode, can be at the switch that causes this?
Engine symbol light was kindled. Hare no switch test to see what happens. Does this engine light goes away by itself or star diagnosis necessary?
Thank you.

Halex Crow.
Problem solved, misplaced transistor was backwards.

Circuit works properly.
Thank you.

 

[Alex Crow]

Halex Crow.
Problem solved, misplaced transistor was backwards.

Circuit works properly.
Thank you.

Easily done! Glad you have it sorted now.

 

[maipac]

Hi Alex Crow.
Is this circuit can be applied without any problem, for vehicles w211 with particulate filter? Thank you.

 

[mercuxio]

So what are your mileages with this mod? Any apparent problems ?

 

[Alex Crow]

Hi Alex Crow.
Is this circuit can be applied without any problem, for vehicles w211 with particulate filter? Thank you.

Hi, sorry but I cannot give a definite answer to this.

Although I can see no reason why the mod should affect DPF function, it is impossible for me to say it will not cause any problems.
It is possible that the mod will slightly reduce particualate emissions, helping the DPF, or equally it may produce more - cannot be sure.

 

[Homebrewer]

Hi Alex Crow.
Is this circuit can be applied without any problem, for vehicles w211 with particulate filter? Thank you.

My w211 has a particle filter and so far no problems what so ever. I think it should help keep the particle filter clean because of less particles being generated and a slightly higher exhaust temperature. Time will tell.

 

[Homebrewer]

Alex,
I have driven my car over 1000 miles so far with the mod and have had absolutely NO problems. The idle on start-up is much smoother now, fuel economy has increased by about 2 mpg, and the car seems to accelerate quicker and more smoothly. Additionally, I now know that I will not have a clogged intake manifold from all the exhaust gasses passing through the intake. Thanks again!
steve

 

[AdamG]

I have done about 1000 miles since mapping out the egr. I have not noticed much difference with regard to idle or mpg.

I would say the pickup is slightly better but the biggest difference is the smoke. Previously if I was cruising then floored it there would be a big cloud of smoke. Now I can not see any in the rear view mirror even at night.

My car does not have a dpf but I would think that the reduced smoke would help it significantly.

Adam

 

[mercuxio]

AdamG, perhaps your EGR was clogged up a bit to bein with. Hence the minor difference?

The lack of smoke has it's pros and cons. It's a nuisance normally but useful to surprise tailgaters

I'm gonna build the "box" for this. Based on the wiring etc, I believe all connections can be done within the apparatus box that holds the ECU. I have that apparatus box modded with "active" cooling. The components will probably benefit a little off the cooling. Gonna try a make it small and neat. Will update with pics once I get it done.

On another note, I have a phobia with connection mods to the ECU. Replaced my ECU a while back (a lot of $$$). Somehow something within the ECU just decide to fail. I have even remove the SprintBooster that was in there when I bought the car. Do you guys think the SprintBooster would have been killing the ECU gradually?