What Citroen codes (P244A, P0401, P0562, P0299, P0420, P0016) actually mean on Citroen engines — the real cause, the common misdiagnosis, and the honest UK repair cost.
These are the OBD fault codes we see most often on Citroen vehicles in the workshop, with the real cause on Citroen engines rather than the generic textbook definition, plus the honest independent-garage cost.
Citroen fault codes explained
- P244A — Differential pressure across DPF too low — on Citroen 1.6/2.0 HDi this is usually the pressure sensor or split pipework, not the DPF. Typical UK cost £60–£1800.
- P0401 — EGR flow insufficient on Citroen 1.6/2.0 HDi — identical PSA-group issue as Peugeot, very common on C3/C4/Berlingo doing short runs. Typical UK cost £180–£720.
- P0562 — System voltage low on Citroen — PSA Smart Charging system issues plus BSI (body computer) charging-strategy faults common on C3/C4. Typical UK cost £100–£420.
- P0299 — Turbo underboost on Citroën — PSA HDi VGT actuators and PureTech wastegate solenoids are the typical failure points. Typical UK cost £160–£1500.
- P0420 — Catalyst efficiency below threshold on Citroën — PSA THP and PureTech petrols suffer cat degradation from oil burning. Typical UK cost £240–£1300.
- P0016 — Crank/cam correlation Bank 1 on Citroën — 1.6 THP/VTi Prince engine timing chain stretch (DS3, C3, C4 Picasso). Typical UK cost £600–£2400.
- P2002 — DPF efficiency below threshold on Citroën HDi — same DV6/DW10 Eolys-additive story as Peugeot. Typical UK cost £140–£1400.
- P0087 — Fuel rail pressure too low on Citroën — 1.6/2.0 HDi mirroring Peugeot's lift pump / DRV story. Typical UK cost £180–£1400.
- P2463 — DPF soot accumulation on Citroën HDi — same Eolys/DPF story as Peugeot (C3/C4/Berlingo). Typical UK cost £140–£1400.
Codes are generic across manufacturers, but the fix is not. The same code on a Citroen usually points at a different component than it would on another make, which is why a make-specific diagnosis saves money before any parts are bought.