EGR - fault code p0402

Hello,
When i read the fault codes of my c3 1.4 hdi year 2004,
the obd scanner gives the fault code p0402

It is a problem related to the EGR.
Where is located the EGR?
How can i dismount it, to check it?
Thank you!!

vicolodo wrote:Hello,
When i read the fault codes of my c3 1.4 hdi year 2004,
the obd scanner gives the fault code p0402

It is a problem related to the EGR.
Where is located the EGR?
How can i dismount it, to check it?
Thank you!!

Yes, EGR related, so it could be the valve or the valve control.

The EGR can be seen in the pictures of this 16v 1.4 HDi which is very similar, but not identical to the 8v. You can get a good idea of where the EGR is. You EGR may be controlled by a vacuum pipe and a solenoid so these should be checked too, otherwise is electronic and electrical testing will need to be done.

tips-for-a-diesel-powered-citroen-c3-f6 ... -t289.html


The vacuum controlled EGR on a C3

The EGR Valve is located behind the air filter housing (must be removed) under the fuel filter.
It's pretty easy to get off but a tricky to get back on.
Don't drop the screws or gasket or you might look for them for a really long time.

To remove the EGR you must:
a. remove air filter housing
b. undo clip between EGR unit and exhaust pipe
c. disconnect vacuum pipe from EGR
d. remove 2 screws of EGR and It's thin metal gasket (part 6) and don't drop anything.

reassemble in the reverse order.

Like Arfur said, you need to

1. check for proper function of the vacuum solenoid (part 1)

You can do this by either
a. feeding it 12v manually (white wire -, blue wire +) and checking if air flow changes
b. while engine is on, disconnect vacuum pipe going to EGR and put your finger on the connection to see if the air flow changes while someone plays around with the accelerator pedal.
Do this for a short time, since unfiltered air is entering your engine.

2. check for leaks in the vacuum hoses (part 3)

Disconnect hoses, seal with finger on one side and create vacuum on the other side (you can just use your mouth)

3. check for proper opening and closing of the EGR and for a hole in It's diaphragm. (part 5)

create suction on EGR's hose connector.
Check if vacuum holds
check if EGR exhaust door opens and closes freely (you can try to clean it or just buy a new one.)

Thank you very much!!
I will try.
I have a question too, perhaps related to the EGR.

My car has also the problem that consumes the coolant.
It does not leak the coolant, there are no spots under the car, and the motor is dry.

Can this problem be related to the malfunctioning EGR valve?

I see that the EGR is located near the thermostatic valve, can exist some interaction of the two valves?
Thank you!

vicolodo wrote:I have a question too, perhaps related to the EGR.

My car has also the problem that consumes the coolant.
It does not leak the coolant, there are no spots under the car, and the motor is dry.

Can this problem be related to the malfunctioning EGR valve?

The EGR is the Exhaust Gas Recirculation (back into the intake). Its not connected to the cooling system or any EGR faults cause any coolant problems.

You could have a very small leak in a coolant pipe that is difficult to detect because it evaporates quickly or its a head gasket type of problem when the coolant is entering the combustion chamber.

Thank you very much C3driver52

I hoped to solve two problems doing only one fix

I am going to open a new topic about the check of head gasket.

Thank you.