How To: Fix p1434, p1434, eolys additive pump on newer (2017+) Models.

[Ploeckes]

Hi everyone,

this forum has helped me a lot with the issues I encountered, when I was trying to fix my car. So I wanted to give a step by step introduction on how I solved it.

First off, I own a 2017 Citroen Spacetourer 1.6 (blue?) Hdi, ~240.000km. As I have not tried on other vehicles I can not say for certain if this works for other cars, but I assume it would be similiar, at least for the Berlingo and Jumpy models.

The issue arised when my motor engine check light went on with the message "Engine fault repair needed" (or something similar). After diagnosing with my generic testing equipment I got the errors P1434 and P1435 (mulitplexed pump fault).

With some searching I found the correct replacement part (part number 9817154080 in my case), bought it and filled it up with the correct eolys fluid.
Changing the parts didn't fix anything yet thought, so I had to order a Citroen Diagnostic Tool (Full chip!) and I also downloaded one of the available VM (virtual machine) with offline Diagbox v9.xx.
With the Diagnostic tool I was able to tell the ECU that the Additive pump had been replaced. This didn't fix things either.
In my case, the Pump has it's own Control unit. Telling this device, that I changed the pump still gave me the same errors, but I noticed the Control unit was trying to build an Internet connection. Also, fault reading claimed that the tank was empty, which resulted in an error in the BSI, ECU and the addtive control unit.
There is not a lot of information on what actions need an online connection for the new 2016+ models, but I gave it a shot, bought a token and downloaded the official diagbox from the citroen service portal.
Finally, I was able to select part replacement on the additive control unit, and the new tank started clicking/pumping. Keep in mind that the pump is a simple magnetic valve, so the clicking is expected.
Diagbox tells you to wait for up to ten minutes for the pump to finish priming (filling the pipes). In my case the pump was still running after 1h, though the errors had all gone (you have to delete them an check if they reapear!).
I guess my pipes were empty from a mistake we made when filling up the tank, but the clicking went away after a few days.

This whole journey has been quite annoying and at times painful, so I tried to write down what I would've liked to know when I encountered the issue.

The costs for this were:
- the replacement part
- the diagnostic tool if you don't already have one (~100€)
- the token (~50€)
- frustrating hours trying to figure things out

Overall I'm happy I finally got this to work, but if it's the only issue with your car right now you might also be good off just letting a dealer do it for you.