Fault code: EMS 5124 SCANIA

Error identification:

The venturi cannot be operated correctly.

Cause:

The venturi is jamming because of a mechanical fault or insufficient pressure at the control cylinder. There may also be a blockage in the valve block port for the relief valve which drains any remaining pressure.

Notes:

The engine control unit switches off the EGR system and calibration of the mass flow sensor is switched off.

If the venturi is stuck in the closed position, the pressure drop over the venturi will be too great at a high engine speed and heavy load. As a result the charge pressure becomes too low, which may limit the performance and lead to black smoke.

Action:

Check the venturi and the control cylinder.

Check whether the on/off valve is leaking.

Check whether pressure can be released via the valve block.