Variant 1
Applies to: AUS4 (CUI)
What does Scania AUS fault code 85 mean?
Open circuit to input signal.
What causes Scania DTC 85?
- Fault in harness-to-component connector. - Fault in cable harness. - Fault in the microphone U24.
What are the symptoms?
The electronic control unit cannot receive signals from the microphone. The microphone is not working.
How to fix Scania AUS fault code 85?
- Disconnect the microphone from its cable harness.
- Switch on the voltage with the starter key and measure the voltage between signal and earth.
- The measurement result should be approximately 8 V.
- Check for an open circuit in the rest of the cable harness between the microphone and infotainment system.
- If the fault is not in the cable harness or the microphone, it is probably an internal fault in the infotainment system.
- Check that the control unit has the latest software.
Variant 2
Applies to: AUS4 (CUI)
Detection
Open circuit to input signal.
Possible cause
Possible causes: - Fault on the harness-to-component connector - Fault in the cable harness - Fault in the microphone U24
System reaction
The electronic control unit cannot receive signals from the microphone. The microphone is not working.
How to fix
- Disconnect the microphone from its cable harness.
- Switch on the power and measure the voltage between signal and earth.
- The measurement result should be approximately 8 V.
- Check for any open circuits on the rest of the cable harness between the component and the electronic control unit as described in step 1.
- Measure the resistance on the microphone.
- The measurement result should be approximately 200 ohms.
- If the fault is not in the cable harness or in the microphone, it is probably an internal fault in the electronic control unit.
This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.