EGR Valve: how to understand if it works or not

I write this article because it often happens that an engine can start to sob, to have no gaps and make it as good as before.
Sometimes after a while that these symptoms can turn on a lamp on the instrument panel indicating an anomaly to disappear suddenly or to remain on indefinitely.
To check for yourself if the problem of this performance degradation is the famous EGR can be done as follows.
WARNING: It must be said that you can not go around the streets without the EGR connected because the car is no longer suitable for circulation.

CAUTION: DO NOT ASSUME ME RESPONSIBLE OF DAMAGES THAT MAY BE CAUSED DURING THE OPERATION TO PROPERTY AND / OR PEOPLE. ALL WORK MUST BE PERFORMED BY AN EXPERIENCED PERSON. THE TRANSACTION IN QUESTION IS VOID THE WARRANTY. DISCONNECT THE BATTERY DURING THE OPERATION.

The following photos were taken on an Opel/Vauxhall Corsa Sport 1.3 CDTI (engine is also known as multijet). In other engines the valve position changes but it is easy to spot: just follow the exhaust manifolds, a pipeline from the junction leading to our smallest EGR.

Position of EGR valve

The valve is connected to an electronic control coming from the controller, typically the wires are 2 but the size of the connector can be bigger. In the connector of my engine (in the picture) had 6, but the wires were still 2.
If the connector is plugged with small panels or other things, if possible, remove them to facilitate the work and then disconnect the connector.

Connettor EGR

Connettore EGR

Check with a multimeter the resistance of the EGR valve using the same connector on the EGR. Cover with tape so that connector opening to keep dust and dirt.

Acquire a resistance value in ohms with 5W equal to that just measured (in this case were measured 86 ohms, the resistance from 82 ohms with 10% waste is about 0.30 €).

The procedure now requires a little dexterity but not at all difficult.

Cut a cable (of those common current) of a length such as to allow to connect to one end of the connector that comes from the EGR control unit to the resistance purchased placed in a protected position.

Then connect 2 sockets at one end of the cable while the other weld strength.

How to connect faston to control module connector

Another picture

How to connect the resistance

Once you isolate the resistance welded well with electrical tape or better with the rubber tubing. Then place the cable connecting it to the connector and secure with bands along the route to avoid coming into contact with moving parts of the engine or with parts too hot.

Example of fixing the wires

Once the cable is in position to isolate and to fix the contacts in the connector: the faston, in fact, with the vibrations from the engine in motion may leak from the seat and the dust, in turn, could infiltrate compromising the correct functioning.

Once the procedure put any parts moved to facilitate the work. In the photo is an example of how the engine looks after the work.

In position

Engine without cover

Engine with cover

Now that we have “emulated” the EGR valve can try to start the engine before checking nonhardly you turn on the instrument panel does not appear strange errors. In this case do not start up and restore the original connection. If the error persists, disconnect the battery, wait at least 10 minutes and reconnect.
Just put the engine should not be visible errors on the instrument panel, if that were not restore the original connection. If the error persists, disconnect the battery, wait at least 10 minutes and reconnect.
Trying to put the car in motion (I repeat that it is not allowed to move with the change and avoid travel on public roads) if the valve is defective it will be appreciated greatly improved fluidity at low speed and any “hiccups” or loss of power disappear.
If, therefore, the valve is faulty you should clean or replace if they are excessively worn. Continue with the pilot light resistance can lead to error or generic anti-pollution (on a FIAT badged model). In this case the engine off, waiting about ten minutes and then on again the light goes off.
If there is no difference and the machine continues to have problems restore the connection with the EGR valve and control the flow meter and, in case of diesel engines, the fuel filter.

Any suggestions are welcome.