C5 P0411 P1544 Error Codes

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C5 P0411 P1544 Error Codes

Post by KorbenDallas »


My C5 2003 1.8 Petrol Automatic drives normally without issues but after being serviced at the dealer, I got the "Service" light and the "Check Engine" light.

In order to have an idea, I bought an ELM adapter and installed the FAP App, scan codes and received one code "P0411", after some search I found "Secondary Air System", so, dismantled the secondary air pump, which was really dirty, cleaned, lubed, assembled. Cleared the code and made a weekend trip.

No problems at all, but, after 150 km, and three days, I got the message again "Pollution Fault", another check, the same code "P0411".

Check all the connections, hoses, etc. Cleared the code. No issues.

Same as before, "Pollution Fault" but this time I got two codes P0411 and P1544, the last one I can´t find any info, only two "causes", Low Gas Pressure (AC) or Idle Valve, but the car still drives normal, no issues at all. the only change is when I clear the codes the automatic gearbox change gears with some roughness. surprisingly, when it shows the codes, the auto changes smoothly.

Fast forward until today, I bought a Diagbox scanner and an old laptop with Windows 7. Finally, everything is installed and running.

Tried to connect to the car, open Diagbox V 07.02, connect the VCI with the laptop, and then with the OBD port in the car.

Select Citroen, C5, read the VIN number, ask for the RPO number, shows two buttons "Lexia" and "Scantool", select "Lexia" and nothing happens.

Tried many times, after restarting the laptop, opening Diagbox first and waiting for it to ask to connect the VCI, and then to connect to the car, and nothing happens after I insert the RPO number, only the screen showing LEXIA and SCANTOOL.

So, scan again with the ELM Bluetooth adapter and the FAP app and still the two same codes P0411 and P1544.

I'm running out of options, so, any ideas about the Error Codes? Any suggestion in order to connect the Diagbox?

I'm also trying to connect a Bluetooth Adapter in the CD Changer connector, but I need to activate the "CD Changer Option" in the Diagbox. I'm simply trying to keep the original radio but would like to listen to the GPS direction on my cellphone and the Spotify playlist.

Thanks in advance for any help you can provide me.
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Re: C5 P0411 P1544 Error Codes

Post by GiveMeABreak »

P1544: Concerns the Gear selection actuator electric motor control fault: Coherence
I'm not getting anything for P0411 sorry, it's not a code showing up for the 1.8 Petrol.

Unfortunately with these early petrol vehicles, there's very little on fault codes.
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Re: C5 P0411 P1544 Error Codes

Post by wheeler »

Is the air pump actually working? You should easily be able to hear it running, they are normally fairly loud. It should run for about 2 minutes after starting the engine from cold & idling.
If its not operating disconnect, apply 12v & earth directly to the terminals & it should start pumping.
Report back with the results.