239174 | Genuine Mitsubishi FUSO® Urea Tank Supply Pump Module

1. Supply DEF to the emissions system

The pump module moves Diesel Exhaust Fluid from the tank to the exhaust system. The fluid is then injected into the exhaust as part of the Selective Catalytic Reduction (SCR) system.

Without the pump, the DEF cannot reach the injector, so the emissions system will not work.

2. Reduce harmful emissions

When DEF is injected into the exhaust, it reacts with nitrogen oxide gases (NOx) and converts them into harmless nitrogen and water vapor. This significantly reduces air pollution from diesel engines.

3. Control the correct fluid pressure and flow

The pump module ensures the DEF is delivered at the correct pressure and amount required by the engine control system. This helps the SCR system operate efficiently.

4. Monitor system operation

Many pump modules also contain sensors that monitor:

• DEF temperature 

• DEF level 

• System pressure

This information is sent to the engine control unit so it can adjust the emissions process.

5. Help vehicles meet emissions regulations

Modern diesel engines must meet strict environmental rules set by agencies such as the United States Environmental Protection Agency. The urea supply pump module is essential for meeting these standards.

1. DEF or emissions warning lights

• The dashboard may show “DEF System Fault”, “Check SCR System”, or low DEF warnings even if the tank is full.

• Sometimes the check engine light also comes on.

2. Reduced engine power (derate)

• Many diesel vehicles limit engine power or vehicle speed when the SCR system detects DEF supply issues.

• This is a protective measure to prevent excessive emissions.

3. Engine or DEF fault codes

• A scan tool may show codes like:

  • P20EE / P20EF (DEF Pump Performance or Flow)

  • P208E (DEF Delivery Fault)

4. DEF not being consumed

• If you refill the tank but the DEF gauge doesn’t change or fluid doesn’t seem to move, the pump may not be working.

5. Strange noises from the pump

• A failing pump can make grinding, buzzing, or whirring noises, indicating mechanical failure.

6. DEF freezing issues

• Some modules have heating elements. If these fail, DEF may freeze and the system may show a fault, even in mild cold weather.