Fault code: 55046 SCANIA

Error identification:

The supply pressure does not decrease fast enough when the engine is shut down with the fuel shut-off valve.

Cause:

Possible causes:

• The fuel shut-off valve is stuck open.

• If fault code 55040 or 55041 has also been generated, there is probably an electrical fault. Otherwise, either the fuel shut-off valve or the fuel supply pressure sensor is faulty.

• Fault in the circuit of the charge air pressure sensor, charge air temperature sensor, coolant temperature sensor or fan speed sensor.

Notes:

There is a common voltage supply for the fuel supply pressure sensor, coolant temperature sensor, charge air pressure sensor, charge air temperature sensor and fan speed sensor. If a fault occurs in one of the sensors, the other sensor circuits may be affected.

When the engine is switched off using the key, the solenoid valves will try to keep the engine running while the fuel shut-off valve transmits a signal to shut down the engine. If this fails, i.e. the supply pressure does not decrease significantly, a fault code is generated and the engine is shut down by the solenoid valves.

The fault code is only generated if there have been three failed shutdowns in succession.

The maximum engine torque is reduced by about 30% as long as the fault is active.

Because the fault code is generated when the engine is shut down, it can only be cleared once the engine has been shut down successfully.

Action:

Check whether fault code 55040 or 55041 has been generated. If so, check the fuel shut-off valve and the electrical cables.

If fault code 55040 or 55041 has not been generated, renew the fuel shut-off valve first of all and then if necessary the sensor for the fuel supply pressure.

Check the fuel supply pressure sensor, coolant temperature sensor, charge air pressure sensor, charge air temperature sensor and fan speed sensor, along with the harness-to-harness connectors and electrical cables in the circuits.