What Renault codes (P0299, P0401, P0203, P0562, P0420, P0341) actually mean on Renault engines — the real cause, the common misdiagnosis, and the honest UK repair cost.
These are the OBD fault codes we see most often on Renault vehicles in the workshop, with the real cause on Renault engines rather than the generic textbook definition, plus the honest independent-garage cost.
Renault fault codes explained
- P0299 — Turbo underboost on Renault — 1.5 dCi K9K and 1.6 dCi R9M commonly suffer turbo oil starvation and actuator failure. Typical UK cost £250–£1800.
- P0401 — EGR flow insufficient on Renault 1.5/1.6/2.0 dCi — sticky EGR valve and intake carbon, often paired with swirl flap issues on dCi 130/160. Typical UK cost £160–£680.
- P0203 — Injector circuit Cylinder 3 on Renault 1.5/1.6/2.0 dCi — Delphi injectors fail electrically, plus wiring harness corrosion on vans. Typical UK cost £180–£720.
- P0562 — System voltage low on Renault — alternator decoupler pulley failure on 1.5 dCi (often misdiagnosed as battery) plus harness corrosion on vans. Typical UK cost £80–£420.
- P0420 — Catalyst efficiency below threshold on Renault — 1.2 TCe, 1.6 dCi rare, but 1.2 TCe is the headline case. Typical UK cost £260–£1400.
- P0341 — Camshaft position sensor performance on Renault — 1.5 dCi K9K and 1.2 TCe H5F sensor failure. Typical UK cost £60–£260.
- P0011 — VVT 'A' over-advanced Bank 1 on Renault — 1.2 TCe H5F and 1.6 dCi R9M VVT solenoid and oil sludge. Typical UK cost £65–£480.
- P0087 — Fuel rail pressure too low on Renault — 1.5 dCi K9K and 1.6 dCi R9M lift pump / DRV. Typical UK cost £180–£1300.
- P2002 — DPF efficiency below threshold on Renault — K9K dCi DPF clogged with belt-in-oil debris (newer engines) and Megane regen failure. Typical UK cost £180–£1600.
- P2463 — DPF soot accumulation on Renault dCi — K9K/R9M over-soot, belt-in-oil contamination risk. Typical UK cost £180–£1600.
Codes are generic across manufacturers, but the fix is not. The same code on a Renault 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.