Problems with Air mixer and EGR cooler C5 X7 163

[piliotov]

Dear fellow car owners,

My Citroen has the DW10CTED4 163hp engine and I recently got a warning on my dash stating there was an issue with my FAP regeneration. Decided to buy an AliExpress OBD for Diagbox and after reading the codes there were two codes in the ECU one was for the air mixer and the other for egr cooler both not functioning.

I then investigated further and did the actuators tests with the diagbox, for the air mixer the test got cancelled for some reason and for the EGR cooler valve it gave back an error the valve was stuck due to build up. I then checked both valves, moved them by hand and they moved freely and were under certain tension from their springs.

Then disconnected the vacuum line to the EGR cooler and started the engine cold, and there was no vacuum on the line.

Where may the problem be? Can it be a solenoid, are they both connected to a single solenoid and it could have gone bad? What should I test further?

Just to make sure I leave no details out, my engine has the EGR body on the front with the cooler as well, the air doser has two inlets and they both have vacuum flaps. All of the flaps including the EGR cooler are moving freely by hand.

Thank you very much for your time and help!

Best,
Ilia

[mickthemaverick]

My first reaction to your post is that you have a vacuum leak or maybe a blockage in a vacuum line. Have a read through this site which may help you work out your issue: https://www.guyscars.co.uk/how-to-map-o ... egr-valve/