C5 2003 permanent fault.

[Spix]

Dears,

As per picture attached this permanent error cannot be removed, any advices?
Obviously tank of additive is filled.

Thank you and happy new year!

[PaulC5]

If you have filled the additive tank up it then needs a diagnostic to tell the car it has been filled since the level is not measured, just calculated from the number of times it has been filled with diesel.

[Paul-R]

This is a 2.2l HDi engine and I'm pretty sure that I've read that there are problems with these very early implementations of Eolys. I think that you may have to tell the system in two separate places that it's been refilled. Equally, there's a nagging thought that I have also read that this is not something that can be reset and might even need a replacement ECU somewhere.

Hopefully, this will jog someone else's (better) memory and they will be able to elucidate.

[RichardW]

To clear the fault you need to perform the service action to tell it the tank has been refilled, this will then allow the fault to be cleared. However as Paul says on these early cars sometimes the additive ECU will refuse to accept the service action and can't be reset - in which case replacing the ECU is the only option. This may be a challenge for a 20+ year old car.... The only other option left might be to turn it off in the BSI and then just add 5ml of the additive to the tank each time you fill up.

[Spix]

To clear the fault you need to perform the service action to tell it the tank has been refilled, this will then allow the fault to be cleared. However as Paul says on these early cars sometimes the additive ECU will refuse to accept the service action and can't be reset - in which case replacing the ECU is the only option. This may be a challenge for a 20+ year old car.... The only other option left might be to turn it off in the BSI and then just add 5ml of the additive to the tank each time you fill up.

Actually, I’ve managed to get a used ECU aditive (though I’m not sure if it’s fully functional yet). I’d like to give it a try, but I have three questions:

1) Location: Where exactly is the additive ECU located? I need to know where to find it to perform the replacement.
2) Safety: Do I need to disconnect the battery before swapping the units?
3) Configuration: Since the new unit will have a different serial number, does Diagbox have a specific 'learning' or configuration section to initialize it?

Thanks to everyone for the amazing support you’re providing!"

[aspire_helen]

Re Eolys / DPX42 dosing rate is 37.5ml per 60ltrs of diesel (2001 C5 2.2HDi). Ive been adding it manually for several years now since the additive ECU packed up, no problem at all. At least I know the Eolys is actually been added !!
The Additive ECU can be in different places. On mine it is in the rear right passenger footwell. Prise off the plastic trim forming the door threshold.

[Spix]

Thank you