Fault code: EMS 8384 SCANIA

Error identification:

Internal fault in the main unit.

Cause:

One of the sensors inside the main unit is short-circuited to battery voltage.

Notes:

As a result of the fault, the SCR system is deactivated and injection of reductant stops.

The SCR system communication related fault codes 4108, 4106 and 4107 can be generated when the SCR system is deactivated. Carry out troubleshooting using this fault code in the first instance.

When the SCR system is deactivated, communication between the SCR control unit and the engine control unit may be interrupted. To ensure correct fault code handling, the control units must be able to communicate with each other. Try to re-establish communication by switching off the ignition voltage and then waiting 90 seconds before switching it on again.

The fault affects the vehicle s emissions of nitrogen oxides (NOx) and the lamp which warns about a high level of contaminants comes on in the instrument cluster. A text message is also displayed in vehicles with NOx monitoring.

Vehicles with NOx monitoring

An active fault code limits the maximum engine torque by approximately 40%.

An active fault code cannot be cleared from the control unit. When the fault has been rectified, the control unit must verify that the fault has been rectified in order for the fault code to become inactive.

Action:

Switch off the ignition with the starter key, wait for 90 seconds and then switch it on again with the starter key. If the fault code becomes inactive clear the fault code, if the fault code is still active the main unit must be renewed.

Proceed as follows to verify that the fault has been rectified:

Switch off the power with the starter key, wait for at least 90 seconds and switch on the power with the starter key again.

If the fault is resolved, the fault code becomes inactive. Clear the fault code.

Switch the power off and on with the starter key three times in succession at 10 second intervals to turn off the warning lamp.