c5 hdi 2.0ltr 2003 LX

Clogzz · Unread post by **Clogzz** » 17 Oct 2010, 12:25

Blanking off causes the EGR to detect that it doesn’t work properly, so the codes are back.
An EGR electrovalve has five wires; two to operate the valve, and three to detect its position.
Blanking off at the red arrow pushes the valve in, and the electronics will find out.
Blanking off at the far end prevents recirculation, and the airflow meter will tell the electronics.

boristhespie · Unread post by **boristhespie** » 17 Oct 2010, 14:20

HE said they were blanking off the egr to prevent exhaust gases being reused.

The faults are Airflow and Relay circuit.

cachaciero · Unread post by **cachaciero** » 17 Oct 2010, 20:36

In any control system that uses a modern electronics box with electro-mechanical device / devices on it's inputs or outputs by far and away the most common failure items will be the electro-mechanical bits.

It has already been suggested by clogzz that what the garage has done does not eliminate a stuck EGR valve.

So I would not consider the ECU without first trying to prove conclusively that the EGR valve is good.

One thought is that if this valve has a position sensor I would have thought that the position could be read using a Lexia if so it becomes easy it either moves or it doesn't.

Note I don't have a 2.0 ltr so the last para is a bit speculative.

cachaciero

boristhespie · Unread post by **boristhespie** » 20 Oct 2010, 18:28

What will I suggest or ask the guy

wheeler · Unread post by **wheeler** » 20 Oct 2010, 19:58

Clogzz wrote:Blanking off causes the EGR to detect that it doesn’t work properly, so the codes are back.
An EGR electrovalve has five wires; two to operate the valve, and three to detect its position.
Blanking off at the red arrow pushes the valve in, and the electronics will find out.
Blanking off at the far end prevents recirculation, and the airflow meter will tell the electronics.

That's not the case on this engine, the EGR valve is vaccum operated via the (2 wire) electrovalve & there is no position feedback sensor.[/quote]

cachaciero · Unread post by **cachaciero** » 20 Oct 2010, 21:12

In light of wheelers comments one thing I would check is the vacuum to and from the electro-valve. If a vac gauge is T'eed into the O/P from the electrovalve then with the engine running and the electro-valve energised either using the facility built into the Lexia or by directly applying volts to the connector on the EV it should be possible to see the level of vacuum applied to the EGR.

If that looks sensible then the only thing else I can think of is physical examination of the EGR i.e take it of and have a look to see if it's stuck.Note I don't know how easy it is i.e how many hours it would take to do this.

What do you tell the guy? suggest you print out the last few posts on this thread and discuss with him, anybody half reasonable should at least give the wisdom here in written some thought and consideration.

cachaciero