C5 II 1.6 HDi Exhaust system defect

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Dav03k
Posts: 7
Joined: 15 Apr 2022, 22:52

C5 II 1.6 HDi Exhaust system defect

Post by 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.
Attachments
20220415_203622.jpg
20220415_203632.jpg
20220415_203641.jpg
RichardW
Forum Treasurer
Posts: 9875
Joined: 07 Aug 2002, 17:12
x 553

Re: C5 II 1.6 HDi Exhaust system defect

Post by RichardW »

Those are showing as permanent faults. What happens if you try to clear them, do they go away and come back again?
Dav03k
Posts: 7
Joined: 15 Apr 2022, 22:52

Re: C5 II 1.6 HDi Exhaust system defect

Post by 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
Posts: 7
Joined: 15 Apr 2022, 22:52

Re: C5 II 1.6 HDi Exhaust system defect

Post by 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
Forum Treasurer
Posts: 9875
Joined: 07 Aug 2002, 17:12
x 553

Re: C5 II 1.6 HDi Exhaust system defect

Post by 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
(Donor 2020)
Posts: 54
Joined: 07 May 2020, 09:19
x 5

Re: C5 II 1.6 HDi Exhaust system defect

Post by 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
Posts: 7
Joined: 15 Apr 2022, 22:52

Re: C5 II 1.6 HDi Exhaust system defect

Post by 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
(Donor 2020)
Posts: 54
Joined: 07 May 2020, 09:19
x 5

Re: C5 II 1.6 HDi Exhaust system defect

Post by cit-rotti »

Dav03k wrote:
30 Apr 2022, 09:06
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.