P0400 Code

[grasmere59]

Hi All,
My 110 HDi has thrown up this fault a couple of times over the last week,no limp mode just eml light and when read it comes up with P0400 "EGR Incorrect Output" issue,first eml in 13 years of ownership!
Where should i start first? Remove the EGR and clean it or do you reckon it could be the solenoid on the bulkhead or can i disconnect the solenoid and vacuum pipes and run like that?
Any advice appreciated

[Doggy]

You can certainly disconnect/plug the vaccum pipe from the EV to the vaccum pump/servo, (no need to touch the one from the EV to the EGR).
Disconnecting the EV electrically will cause an error, something to the effect of 'solenoid open circuit'.

Disconnecting the vacuum pipe as above and/or blanking the EGR pipe caused an intermittent fault, something to the effect of 'air flow too high' on my 2.2 HDl's, but never lit the EML. (Understandable because the ecu expects to see reduced mass air flow when the EGR's open which obviously won't happen with it disabled).

Hope that helps?

[grasmere59]

Cheers Eric,i'll give that a go

[GingerMagic]

Thing is, a 110Hdi will light up the EML if you disconnect the solenoid - whereas the Hdi90 is more forgiving..

Just check the vacuum pipes for any splits, or just replace them with some from eBay or something - might not fix it but it's worth doing as a matter of course.

You can also swap the connection/pipes from one solenoid to the other just to eliminate the solenoid as the issue.

While you are under the bonnet having a fiddle, you can test the EGR is not sticking by following the pipe from the EGR to the solenoid, disconnect it and suck on the end - you should hear a metallic ping if the EGR is opening and closing - no ping means no movement.

I'm also sure you can blank the EGR on a 110 - blanks are cheap enough

Let us know how you get on.

[grasmere59]

Will have a go at the weekend if i have time,i reset the eml yesterday and not back on yet,thing is luckily no limp mode so no real rush to sort it,mot's not till november

[grasmere59]

Well i blanked off the solenoid valve vacuum inlet and outlet and eventually after a few miles it through up the code again,i suspect the valve is faulty,does anyone have the part number for a new one? Are both the egr and turbo solenoids the same?
Cheers

[GingerMagic]

It's 1628HC if I remember correctly.

Both solenoid valves have the same part number and the both kinda flutter open and closed but the ECU determines how quick each one flutters depending on demand.

[grasmere59]

Just been out sucking and blowing on the egr inlet and nothing,i can detect no movement so not sure if it is jammed open or shut,buggeration,it looks so easy to get to

[grasmere59]

Would blanking the egr at the cold end stop the eml coming up do you reckon,just looked at the studs at the egr valve and they look akin to something off the Titanic and would snap for sure so egr valve change looks major job.

[GingerMagic]

So it seems your EGR is jammed, however whether this is jammed open or closed is a different story....

I'm pretty certain the rest position for the EGR is closed, and the vacuum pump/solenoid keep it closed until decelerating when the solenoid stops the vacuum so the EGR pings open

No vacuum supply, or a blank plate fitted, the EGR should be permanently closed which would flag a fault unless it's mapped out.

Removing the EGR isn't too bad, access is tricky and the bolts are facing upwards - although once removed you can fit a blank temporarily to keep the car drivable until you can unstick the EGR.

Sadly I don't have a spare I could give you.

[grasmere59]

Strange thing is that the EML seems to pop up on deceleration conditions,i assume it is the MAF sensing the issue and bringing up the EML,the car runs fine with the EML on or off but it's just annoying and will be an issue at MOT or i would just leave it be.