Applies to: AUS4 (CUI)
What does Scania AUS fault code 78 mean?
Open circuit in the circuit to the mid-range loudspeaker in the rear right-hand door. Open circuit in the circuit to the right-hand mid-range speaker. | Open circuit in the circuit to the mid-range loudspeaker in the rear right-hand door. | Open circuit in the circuit to the right-hand mid-range speaker.
What causes Scania DTC 78?
- Incorrect software activates the fault code even though the vehicle should not be equipped with the loudspeaker. - Open circuit.
How does the system react?
The speaker does not function.
How to fix Scania AUS fault code 78?
- Check whether the vehicle has been configured for the loudspeaker.
- In that case, the loudspeaker is present as an electrical circuit under the infotainment system.
- Via the circuit, you can test the loudspeaker function.
- If the vehicle is equipped with the loudspeaker:
- Check the cable harness between the control unit and loudspeaker for open circuits.
- Measure the resistance of the loudspeaker.
- The resistance should be 2–10 ohms.
- If the vehicle is not equipped with the loudspeaker but the fault code is still active:
- Check that the control unit has the latest software.
- Clear the fault code.
This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.