Eolys on my C5??

[Jetjockey]

Hello.

Apologies for the question, but it’s specific to my car. In a nutshell, I cannot find any info regarding whether or not my 2008 C5 Exclusive tourer actually has an Eolys system fitted. I can’t see anything in any of the menus, and I’ve scoured the underneath of the car looking for a filler cap and tank to no avail. Could somebody tell me what’s what please?

Chassis number is VF7**************[VIN obfuscated, can be read by forum staff]

Thanks in advance.

[RichardW]

Yes, it's got one, here's the pic of the tank:

[Jetjockey]

Well, I’ll be jiggered.

Thanks Richard. Now, next question, how do I know if it needs fluid. I’ve had the car for 6 months and the previous owner did 155,000 miles in the car and has no knowledge of any fluid refill. His service history paperwork shows no record of top ups. Surely it must be empty by now?

Also, how is this fluid injected into the system? Is it bled into the fuel tank by suction, or pumped somewhere on command from the engine ECU. I don’t see any electrical items on that diagram.

Thanks.

[GiveMeABreak]

Don't worry about it until it tells you to top it up. Distance remaining is calculated by the engine ECU based on estimated quantity of additive in the tank remaining (it is not physically measured) and the distance until the next due service interval. If it thinks there is insufficient additive remaining until the next service it will flag the warning up to top it up. In either case when the warning comes up, there is generally sufficient for 500 to 1000 miles depending on driving conditions of course.

Injection is controlled by the engine ECU afer deciding on whether, and if so, how much fuel has been added to the tank. The additive system then injects the relevant quality into the tank.

[Jetjockey]

Ok, thanks for that. I’d have thought it would have needed fluid based on the mileage the car has done but there you are.

Where does the warning light / message appear.

Cheers.

[Hell Razor5543]

I don't know where the message will appear (but Marc should be able to let you know), but I do know that you cannot mix the fuel additives (and there are different types). Now he has the VIN Marc can let you know the correct one to use for your C5 (but if you change or add to your fleet you must get the right additive for each vehicle; they may not use the same fluid), and the refilling procedure (including how to reset the counter, which will need access to a diagnostics system known as a Lexia (or, more correctly, a DiagBox system)).

It is not like AdBlue; the additive system does not need to add much to the fuel tank for it to be effective.

[GiveMeABreak]

Ok, thanks for that. I’d have thought it would have needed fluid based on the mileage the car has done but there you are.

Where does the warning light / message appear.

Cheers.

You'll get the SERVICE light on, along with an audible alert and a message on the middle LCD display in the instrument panel: "Particle Filter (FAP) additive level too low"
or very similar.

[bobins]

If you've got a suitable generic OBDII reader, and if you've got a suitable Android device, then you can get a readout of the Eolys tank level by using the Faplite app (free, available Google Play). It'll also do basic fault code reading - but it's not really a substitute for the Lexia / Diagbox diagnostic system in case you were wondering

[Jetjockey]

Thanks bobbins.

I’ve actually got access to either a professional snap on reader or a n other. Both of these can be borrowed for five minutes if I grovel enough. One of those should surely do the trick if I dig into the fuel system?

Thanks.

[GiveMeABreak]

The additive data is available from the engine ECU if using a capable diagnostic tool like Diagbox - can't speak for other systems.

[Jetjockey]

Hello again.

Thanks for all that. I’ve just been out and studied the petrol filler cap very closely, I can’t see any magnets anywhere?
Are there supposed to be magnets to feed the refuelling counter?

Thanks.

[GiveMeABreak]

Not necessarily. You won't see them even if they are there as they are inside connected to the plug detect sensor on the inside - if it has this system.

[Jetjockey]

Ahhhh, sorry.

The sticky “Eolys” thread above somewhere states to check the filler cap for magnets which often fall out?

[GiveMeABreak]

You would get a specific fault code logged if it wasn't functional - P2408 if memory serves - Fuel tank cap sensor signal fault.

I can confirm after checking your VIN you do have the sensor on the fuel cap unit (same engine as mine), but unless you have that code, it won't be that so save yourself some grief on that front.