AdBlue Tank Repair Psa 1.4 1.6

Error Codes:
P20E8 - AdBlue pressure too low

The AdBlue tank with original OE code 9818703780 is an integrated module used on PSA group vehicles equipped with 1.6 BlueHDi Euro 6 engines. The component is an integral part of the SCR (Selective Catalytic Reduction) system and performs the function of storing, pumping, and dosing technical urea (AdBlue) into the exhaust gases to reduce nitrogen oxides (NOx).

Technical characteristics

The AdBlue tank OE 9818703780 has the following features:

• Tank made of plastic material resistant to urea-based solutions
• Storage capacity: variable between 12 and 17 liters depending on the vehicle
• Integrated electric pump for fluid pressurization
• Built-in level and temperature sensor
• Ventilation valve with electronic management
• Multipolar electrical connector for engine control unit interface
• Wired module prepared for CAN communication

The entire assembly is designed to withstand thermal cycles, vibrations, and fluid crystallization, complying with Euro 6 environmental specifications.

DIPA can intervene to overhaul these spare parts thanks to its experience and expertise.

Functionality

The AdBlue tank 9818703780 is responsible for the entire management process of the SCR additive. The urea is drawn from the tank by the internal pump, pressurized, and sent to the dosing valve, which injects small amounts of AdBlue into the exhaust system. This process allows the chemical conversion of nitrogen oxides into nitrogen and water vapor inside the SCR catalyst. The correct functioning of this module is essential to comply with anti-pollution regulations and to avoid power limitation of the vehicle in case of failure.

Brand and model on which the part is mounted

Citroën:

• C3
• C3 Picasso
• C4 Cactus
• DS3
• C-Elysée

Peugeot:

• 208
• 2008
• 301

DIPA recommends always verifying compatibility based on the specific engine code and chassis number.

Defects and causes

The AdBlue module 9818703780 is subject to both electronic and mechanical failures. The most common defects include:

• Internal pump failure: the generated pressure is insufficient and the SCR system does not receive the additive
• Liquid crystallization: at low temperatures, urea can solidify in the ducts and cause blockages
• Level sensor malfunction: the system erroneously signals AdBlue as depleted or absent
• Leaks from the tank: cracks in the plastic body or fittings can cause leaks and unpleasant odors
• Communication error with the control unit: damaged wiring or telecoding problems after replacement

If not resolved, these failures activate engine limitation strategies with messages on the dashboard, such as “remaining starts” or “unable to start the engine.”

Possible associated DTC codes

Defects of the AdBlue tank OE 9818703780 can generate various error codes in diagnostics, including:

• P20E8: insufficient urea pressure in the SCR circuit

Final conclusions

The AdBlue tank with OE code 9818703780 is an essential component for the operation of the SCR system on 1.6 BlueHDi PSA engines. The integration of tank, pump, valves, and sensors in a compact unit allows precise emission control but makes the entire module sensitive to crystallizations, electronic failures, and mechanical degradation.

DIPA supports customers also in after-sales. It can intervene to overhaul these components and restore them to full functionality, saving replacement costs and benefiting the environment through the circular economy.