AdBlue Tank Revision Citroen C4

Error Codes:
P20E8 - AdBlue pressure too low

The AdBlue tank with OE code 9807475780 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 pump module + electronics integrated (unit "tank + pump + control module").
• Equipment: urea pump, level sensor, fluid temperature sensor, integrated filter, heating/antifreeze of the pickup and delivery line; pressure monitoring in the circuit.
• Interfaces: electrical connector 12 V, heated delivery line to the SCR injector, sealed quick couplings.
• Typical capacity: approximately 15–17 liters depending on year/platform and configuration (with/without spare wheel).
• Location: rear underbody (longerons/spare wheel well area), with impact/dirt protection shields.
• Supply: complete assembly, requires priming and initialization in the engine ECU after installation (Denox procedure).

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 reduction of NOx in the SCR catalyst.

Model applications

Citroën

• C4

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 lights, start countdown.
• Level sensor failure → autonomy indicated incorrectly, persistent warnings after refilling.
• Crystallization of the fluid in pipes/injector → restrictions and flow drop.
• Heating anomaly (resistances/heated lines) → delivery block 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 9807475780 is a complete assembly for the SCR BlueHDi systems of C4/DS4/3008. In diagnosis/replacement it is recommended to: check fluid quality and crystallizations, verify sealing and power supplies.

DIPA has a wide range of spare parts: from original to selected aftermarket parts from the best manufacturers on the market. Not only that: it has overhauled components with performance equivalent to new, which allow savings in 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.