C5 II 1.6 HDi Exhaust system defect

[Dav03k]

I have this problem with my Citroën C5 MK.II 9HZ from 2005, that the car thinks that the EGR is broken. It comes with the usual symptoms of EGR brokenness, such as, power drops, especially at around 1500 rpm and the engine doing wierd things. I let my local Cit-Workshop have a look, they told me that the EGR valve had to be replaced. Well, I did that, erased the faults with my lexia and I thought the problem was resolved, but it reappered. I cleaned the wire connectors to the EGR, replaced the air volume sensor on the air filter and also replaced the MAP-Sensor (which the car says was short circuiting, even after replacing). The problem was still there. The odd thing is that the valve itself seems to be working, because there is only little carbon buildup in it, also when driving the board computer shows, that the avarege consuption is approximately the same as Citroën claims it to be with everything working. I performed a BSI reset with lexia via the PDI. Seemed to be working after it. Power, drops only occured very rarely, almost non existent. Today i started the car and then "BEEP" the engine check light goes on again: "Exhaust sytem defect". Like bruh, I just fixed it. Did anybody have this problem before? Do I have to invest hundreds of euros into repairs? I bought my car with a blown turbo btw.

[RichardW]

Those are showing as permanent faults. What happens if you try to clear them, do they go away and come back again?

[Dav03k]

After i clear them, the engine check light and the fault warning goes away, but if you drive for a little bit it comes on again and the power drops, aswell as the rpm fluctuations are still there while the light is out.

[Dav03k]

Ok so I might have found a solution to my EGR problem. I saw a guy on YouTube who was saying that most EGR replacements need calibration after being put into the car. Since the ECU does not know when the new electronic valve is shutting the valve to 0% and when it is 100% open, with other words the computer does not know the valve opening settigs. The new parameters of the valve have to be configured with a Lexia diagnostic tool via the option "replacement parts", then select the ingnition system. Once selected there should appear an option to configure the EGR. I will try this, but currently my DiagBox does not support this function. I might have to update it a few times since I was using v 7.56 until now.

[RichardW]

1.6 HDi EGR doesn't need calibrating since it self calibrates each time the ignition is cycled - that's the whirring you can gear after key off.

[cit-rotti]

...the Diagbox 7.56 contains the LEXIA 3 software for vehicles up to 2007 and is sufficient for DB diagnoses up to approx. mid-2015.
Nothing needs to be updated.
It is possible to update to 7.57 or 7.62 and if necessary also to 7.82 (corresponds to 8.18) - but for a C5 R this makes no sense.
Provided that the interface works properly, all offline work can be done with the LEXIA 3.
If there is no menu item for an EGR calibration, there is none - see message from forum member "Richard W".

Greetings Wolfgang

[Dav03k]

Thank you for your replies. The guy who originally talked about recalibrating the EGR showed it on his Pegout with the same engine. I was thinking that if it can be done on a pegout it could be done on a citroen. Thanks again.

[cit-rotti]

Thank you for your replies. The guy who originally talked about recalibrating the EGR showed it on his Pegout with the same engine. I was thinking that if it can be done on a pegout it could be done on a citroen. Thanks again.

In principle, it is possible to diagnose or make offline changes to a Citroen with the Peugeot software - PP2000 in this case. However, the prerequisite is that the same ECU's are installed.

[Dav03k]

My car was in a workshop for a week and they changed ONE SENSOR. I don't even know which one, but it fixed the short circuiting problems on my other sensors. The EGR problem remains however. There are faults linked to the DPF of my car as well.
P0483 - Cooling function integrated into ECU (fan unit), open circuit or temperature to high
P0422 - Regeneration request too frequent. These might be linked with the faulty EGR, but I don't know for sure. I have to say that a DELPHI EGR was istalled into the car prior to me swapping it to a cheaper chinese AKWH EGR unit. I took the old one apart and the freaking spules of the magnet valve were burnt. The previous owner really did a hell of a job destroying the electronics of this car.
I have made an appointment at my local dealer who charges ludicrous amounts of money for stuff. I will keep you guys updated.

[Dav03k]

Well, the workshop didn't really help me, but I managed to get hold of an original EGR for a 1.6 HDi Citroen. I built it in and it it is working now. All the faults have disappeared and the car works fine now. For those who are looking to replace their EGR valve: Please try to avoid buying aftermarket EGRs they usually do not work. If you want to buy originals just look around the internet. I was able to get hold of a working original EGR from a scrapyard in Romania. They shipped my EGR for about 30€ total (to my mothers place in the country, then she brought it over to Austria on her way home), it had to be thouroghly cleaned of course, since it was a used one. Generally I would suggest getting parts from scrapyards because altough used, they are original parts and quite light on your pocket compared to new parts, the challenge however is to find a good condition one. The vendor should be asked if the piece sold really is as advertised e.g. in working condition. Also, could somebody please explain me the what EGR initialisation does with lexia? Because that appears to help the engine ECU to communicate with the valve after a new one has been put in.

[H4wkeye]

Since my car had EGR changed prior to me getting it I am curious does it need to be recalibrated via Lexia? On a C5 X7 2.0 HDI.

Since I occasionally get intermittent EGR errors pop up but it doesn't affect the car and it clears itself after some time.

[Dav03k]

Now I do not really know for sure, but mine did that too after I changed the EGR. I initialised it with Lexia, then it stopped showing errors after the first drive.
In this descussion Richard W explained that EGRs calibrate every time you cycle the ignition, at least for the 1.6HDi that is.

[H4wkeye]

Now I do not really know for sure, but mine did that too after I changed the EGR. I initialised it with Lexia, then it stopped showing errors after the first drive.
In this descussion Richard W explained that EGRs calibrate every time you cycle the ignition, at least for the 1.6HDi that is.

Thanks! I'll look into it more.

[wheeler]

1.6 HDi EGR doesn't need calibrating since it self calibrates each time the ignition is cycled - that's the whirring you can gear after key off.

I believe this is mainly a self cleaning operation as EGR valves are known to glog up badly with soot, when the engine is switched off the ECU cycles the EGR valve fully open & fully closed quite sharply around 10 times (varies by each specific ECU) to try and keep the EGR valve clean & free moving.

[GiveMeABreak]

That's my understanding too