how to bypass a mk7 egr valve?

[davetherave]

e m light went out after about 40 miles 'nice one' no trip to the stealers!
the van is out of warranty so did the job myself,the valve cost me £95 off the tinternet.
Now back to my findings-the socket on the top has 5 pins three in a row(these are the sensor wires) , plus two(these are the power)apply 12volts too the power pair the valve will open ,swap the pair the valve will close'if you are lucky'
i have removed cover of egr to find lots of carbon caked over everything (me thinks the valve seal failed cloging the lot up ) lots and lots of wd40 ,just a waiting game now.

So to sum up the sensor wires offer a resistance (ohms) the ecu see's this and can tell where the valve is ,ie open or closed or some where in between. So if your valve is stuck like mine and the ecu tells the valve to close or open, the 'resistance '(electrically speaking ) will stay the same(because the valve has not moved). the ecu see's this and can see the valve has gone faulty ,then lights the engine man light and ford gets abit more of your hard earned cash .SO unplugging the egr electrical connector is basically one of the same thing.Plugging a working egr valve back in will remove the light ,to all of you with the light still lit ,you have another fault or a fautly erg valve (yes i know the bloke who you got it off ,said it was working ? ha ha )he would !

[Tdci_boy]

So if we were to introduce a resistance value some where between the 2 I wonder if the ecu would be happy, then blank the damn thing off, if the valve seat broke up, can it be made out of a better material perhaps to prevent it happening in the future

[davetherave]

poss but the ecu is looking for resistance change on startup then a change on running .too much off a headfu*k so two ways too deal with this ,blank and live with em light or every xxxx miles remove egr valve and give it a good old clean .FORD win again.

[coconut]

FORD win again.

Not really, more like Europe wins again

[ake]

I take theres no 'Official' way round it Coconut

[Tdci_boy]

Well Coconut being the clever chap he is may know what is the normal cause of failure, or is it just a case of a poor design that has a built in repair cost to the customer

[STEVE P]

How about that those are clever with electronics could make a box to keep the ECU happy?

It would have to take the input from the ECU and give an out put to the other wires so as far as the ECU was concerned it was all working OK.

Cannot be that difficult can it? All we would need to know is what the ECU is expecting to see and simulate it. Maybe find a funchioning valve and monitor the inputs and outputs?

I would happily spend the equivalent or even slightly more of an EGR valve on such a device and once fitted would hopfully never need touching again.

Any electronic boffins on here?

There is probably quite a market for such a device, I know of somebody who recently paid nearly £500 for a new EGR valve on a BMW fitted.

Steve P

[Tdci_boy]

£500, & we think we got problems

[dojj]

we won't have as many problems as the poor git who's coughing up £500 a throw for an egr valve on his beemer though

[coconut]

I take theres no 'Official' way round it Coconut

TBH ive never really tried to bypass one, cant go experimenting on customers vehicles unfortunately

Well Coconut being the clever chap he is may know what is the normal cause of failure, or is it just a case of a poor design that has a built in repair cost to the customer

What doesnt go wrong with them the 2 pins snap off the center gear, the valve arm seizes in the shaft, teeth shear off the drive and driven gears, water gets inside the PCB and shorts them out..............................think you get the picture the electrically operated EGR's have always given problems since they 1st come out on the cars, just be thankful Transits aren't like C-MAX's where the EGR's need to be reset after replacement apparently

Im still under the opinion that if the center gear is removed stopping the valve opening it shouldnt put the EML on.......in theory , ive got a couple of old EGR's under the bench but no van to try them on

or

if the EGR cooler was blanked off between the exhaust manifold and cooler

[madmark]

there must be a way of blocking this thing off
with the mk6 i am lucky as it is just disconected and doesnt put the manegment light on

[freeway]

Well just to confuse things further I've got a loss of power (intermittent & becoming more frequent) , took it to Ford & their diagnostic system indicated egr valve, but no em light at all (yes, the light works). Last time the egr was replaced under warranty but I had the warning light on full time & in limp mode for more than 50000 km before the morons figured out what the problem was.Why isn't mine tripping the warning light????

[Mike]

A faulty EGR doesn't always put the EML on.

[fedup2]

A faulty EGR doesn't always put the EML on.

What we could do with knowing is why and what failed without causing a light.Surely if this can happen theres an answer somewhere.

[Mike]

What we could do with knowing is why and what failed without causing a light.Surely if this can happen theres an answer somewhere.

When they start playing up you get the rough running, it's not a total failure so I guess there's enough of the correct info still being sent to the ECU.