AdBlue tank Citroen C4 Spacetourer

Error Codes:
P20E8 - AdBlue pressure too low

The AdBlue tank with OE code 9818559280 is a complete module of the SCR (Selective Catalytic Reduction) system used on PSA vehicles with BlueHDi Euro 6 engines. The unit integrates the container, electric urea pump, sensors, and electrical management of the module, ensuring storage, pressurization, and delivery of the fluid to the SCR injector.

Technical features

• Structure: tank made of plastic material (HDPE) with integrated pump module + electronics (unit "tank + pump + control module").
• Equipment: urea pump, level sensor, fluid temperature sensor, integrated filter, heating/antifreeze for the pickup and delivery line.
• Interfaces: electrical connector 12 V, heated delivery line to the SCR injector, sealed quick couplings.
• Typical capacity: ≈17 liters (indicative value for C4 Picasso/Spacetourer; may vary according to version and market).
• Location: rear underbody (longerons/spare wheel well area), with impact/dirt protection shields.
• Variants: versions with/without spare wheel; differences in brackets/line routing.

DIPA can also intervene to overhaul this component, which is so important for the correct functioning of the engine.

Functions

• Storage and pressurization of the AdBlue fluid to supply the SCR circuit.
• Flow/pressure control and pump actuation management for stable dosing.
• Thermal conditioning (antifreeze/defrost) to ensure delivery even at low temperatures.
• OBD monitoring of level and temperature, with management of autonomy/refill warnings and fallback strategies.
• Integration with engine ECU and NOx sensors for closed-loop dosing and NOx reduction in the SCR catalyst.

Model applications

Citroën

• C4 Spacetourer
• Grand Spacetourer

DIPA recommends always verifying the compatibility of the spare part before purchase.

Typical defects

• Low urea circuit pressure due to pump failure, air intake, or clogged filter → AdBlue/motor fault warning lights, start countdown.
• Level sensor failure → autonomy indicated incorrectly, persistent warnings after refilling.
• Fluid crystallization in pipes/injector → restrictions and flow drop.
• Heating anomaly (resistances/heated lines) → delivery blockage at low temperatures.
• Leaks/seepage from the module or fittings → odors, crystalline deposits, connector corrosion.
• Wiring/electronics defects of the module → "range/performance" errors, degraded mode.

Possible DTC codes

• P20E8 – Reducer pressure too low (low pressure urea circuit).

Final conclusions

The AdBlue tank OE 9818559280 is a complete assembly for the SCR BlueHDi systems of C4 Picasso/Spacetourer. During diagnosis/replacement it is recommended to: check fluid quality and crystallizations, verify sealing and power supplies.

DIPA offers a wide range of spare parts: from original ones to aftermarket parts selected among the best manufacturers on the market. Not only that: it offers reconditioned components with performance equivalent to new, which allow savings on replacement and contribute to environmental protection thanks to the circular economy. If the spare part you need is not available, no worries: DIPA can overhaul your part "on demand," restoring full functionality and safety in a short time.