EGR content
Error identification: The amount of EGR gases returned is too low, the amount of EGR gases cannot be increased to the required level.
Cause: The fault can be due to any of the following:
• The damper in the EGR valve cannot be opened. This may be because the damper is jammed, or the control cylinder pressure is insufficient, or because there is internal leakage in the control cylinder.
• The proportional valve may be faulty.
• The damper in the venturi insert may be stuck in the open position.
• Leakage in the recirculation of EGR gases.
• The mass flow sensor may be indicating too high a value, resulting in the engine control unit concluding that the engine is receiving too low an amount of EGR gases.
Notes: The engine control unit switches off the EGR system and calibration of the mass flow sensor is switched off.
Action: Check the damper in the EGR valve, the control cylinder and the proportional valve by activating the components with Scania Diagnos.
Check the key in the venturi.
Check for leaks in the EGR system.
Check the mass flow sensor.
EGR content
Error identification: The amount of EGR gases returned is too low, the amount of EGR gases cannot be increased to the required level.
Cause: The fault can be due to any of the following:
• The damper in the EGR valve cannot be opened. This may be because the damper is jammed, or the control cylinder pressure is insufficient, or because there is internal leakage in the control cylinder.
• The proportional valve is defective.
• The wedge in the venturi insert has stuck in the open position.
• Leakage in the recirculation of EGR gases.
• The mass flow sensor indicates too high a value. This results in the engine control unit assuming that the engine is receiving too low a volume of EGR gas.
• Fault in the fuel temperature sensor circuit or oil pressure sensor circuit.
Notes: The engine control unit switches off the EGR system and calibration of the mass flow sensor is switched off.
There is a common voltage supply for the oil pressure sensor, fuel temperature sensor and mass flow sensor. If a fault occurs in one of the sensors, the other sensor circuits may be affected.
Action: Check the damper in the EGR valve, the control cylinder and the proportional valve by activating the components with Scania Diagnos.
Check the key in the venturi.
Check for leaks in the EGR system.
Check the oil pressure sensor, fuel temperature sensor and mass flow sensor, along with the harness-to-harness connectors and electrical cables in the circuits.