Fault code: 4458 SCANIA

Error identification:

Permanent electrical fault on one or more injector solenoid valves or on the injector electrical cables.

Cause:

Fault in the solenoid valve to one or more injectors or in the electrical cables to the injectors. If the electrical cables to an injector are defective, this can affect all the injectors in the cylinder bank.

Notes:

The control unit continuously tries to use the injectors irrespective of malfunctions.

XPI engine

Cylinder group B on a 5-cylinder engine is cylinders 1, 3 and 4, on a 6-cylinder engine cylinders 1, 2 and 3, and on an 8-cylinder engine cylinders 1, 4, 6 and 7. The fault only occurs when the engine is running.

Gas engine

The fault is on one or more of the connected injectors.

The fault is on one or more of the connected injectors.

Action:

Run Safety precautions for the fuel system.

Disconnect the electrical cable connections both from the control unit and from the solenoid value on defective injectors.

Measure the resistance in the solenoid valve.

Measure the resistance between the cylinder block and the solenoid valve positive terminal and negative terminal respectively. The value obtained should be infinite resistance (∞ ohms).

Check the electrical cable pin connections in the switch to the control unit and the cable grommet in the cylinder head.

Measure the resistance between the positive and negative leads of the electrical cables (disconnected from the injector and the control unit). The value obtained should be infinite resistance (∞ ohms).

Measure the resistance between the positive or negative lead of the electrical cables and the engine block. The value obtained should be infinite resistance (∞ ohms).

If the operating time since the fault code was generated exceeds 10 hours, drain the EGR cooler as there is a risk that condensed water will form in the air-cooled EGR cooler when the EGR system has been switched off. Drain according to the instructions in Workshop Manual, sub-group 01-65.

Check the relay circuit.

Check the injectors in the group.

Check fuses, electrical cables and harness-to-harness connectors.

After repair, start the engine to clear fault codes.