This is the actual system Citroën mechanics use. You can find older versions of "Service Box" (e.g., 2010 edition) on DVD for ~€10-15 on eBay.
and maintenance summaries . Note that a subscription is often required to download. Summary of HDi Engine Maintenance Common Issues to Check Maintenance Tip Injector seal leaks, turbocharger fragility. Inspect for "black paste" around injectors. 1.6 HDi FAP (Diesel Particulate Filter) clogging. Requires specific low-SAPS oil for longevity. 1.6 BlueHDi AdBlue system faults after 60k km. Monitor AdBlue levels and tank pressure. revue technique citroen c3 hdi pdf best