EGR defeat/shunt

[roadrunner1]

Hi, I did the EGR mod today just like it shows in another thread. For the first 5 miles or so it works fine, then I get the engine management light come on and the code is

P0403 EGR Solenoid Circuit an open or shorted condition detected in the EGR solenoid control circuit, after doing the EGR shunt.

Iv'e just been checking the connections again for the 3rd time just in case.
I have,
1000 ohm going to the red/green pin 1
diode going to the brown/green pin 2
470 ohm going to the MAF yellow/white

Can anyone offer any thoughts on why this has happened?

[piper]

theres a pic dose that help

[fester]

Originally Posted by roadrunner1

Hi, I did the EGR mod today just like it shows in another thread. For the first 5 miles or so it works fine, then I get the engine management light come on and the code is

P0403 EGR Solenoid Circuit an open or shorted condition detected in the EGR solenoid control circuit, after doing the EGR shunt.

Iv'e just been checking the connections again for the 3rd time just in case.
I have,
1000 ohm going to the red/green pin 1
diode going to the brown/green pin 2
470 ohm going to the MAF yellow/white

Can anyone offer any thoughts on why this has happened?

It's a long time since I did this and posted it and I don't have the car anymore so my brain is a little fuzzy but you are using a brown/green wire instead of the grey/yellow. Is your vehicle wiring different.

when you say "going to" do you mean you have the wiring mod spliced into the existing wires. You haven't cut and added the components have you.

Do you have the diode the right way around and do you have the splice from the 1000 ohm resistor on the correct side of the diode.

The wires we are interested in are:
Yellow/white (YL/WT) being the Pin 5 wire from the MAF to Pin 12 in the large ECU plug - Mass air flow sensor signal.
Grey/yellow (GY/YL) being Pin 2 in the EGR solenoid wiring plug - EGR solenoid control.
Red/light green (RD/LG) being Pin 1 in the EGR solenoid wiring plug - Fused auto shut down relay output.
The Merc wiring schematic refers mostly to ECU pin outs as they tend to take their wiring connections from the wires close to the ECU as their ECU plugs are different and easier to access. I did my wiring in the section of loom that is the wiring to the EGR plug.

[roadrunner1]

Hi fester, to be honest I connected the 1K Ohm resistor to (RD/LG) first that only left one wire to connect to the other on the EGR plug so I didn’t really take much notice what colour it was.
I followed the diode/resister layout as per the picture in your thread 16-04-2012 EGR defeat for WG 2.7 CRD. I even used the same colour wires so as not to get them mix up.
I soldered 470 Ohm resistor into the MAF signal wire (YL/WT) the other wires where soldered into the wires just down from the EGR plug. I wanted to leave that in place in case I reverted back to the original set up.

Piper, I made mine up just like in your photo.

[piper]

if you the made the shunt the same as mine why didn't you plug the 2 wires into the egr loom plug, then easy to put back orig, pull wires out and plug back on solenoid

[roadrunner1]

Originally Posted by piper

if you the made the shunt the same as mine why didn't you plug the 2 wires into the egr loom plug, then easy to put back orig, pull wires out and plug back on solenoid

I have soldered my wires into the EGR loom near to the plug so that I can put the plug back on if this shunt doesn't work, is that what you mean piper?

[roadrunner1]

So today in an effort to resolve this problem I took everything back out, made another mod with new diode and resistors reinstalled the new mod as per the instructions on this group. After wiring it up I took it for a good run and all was fine with good throttle response. When I got back I run it into the workshop and let it idle. After about 30 seconds the engine tone changed and it sounded as if the exhaust was blowing and the engine warning light was on again. If I take the key out lock then unlock the doors start the engine even at 2000 revs after about 30 seconds the light comes on again. I've even disconnected the battery for 30 minutes but nothing resolves the problem.
Did I do the correct thing by blanking off the pipe from the EGR solenoid to the EGR valve and the other pipe that goes to the solenoid? The solenoid is now in a box on the shelf.