Applies to: AMS1
What does Scania AMS fault code 4388 mean?
The control unit indicates that the voltage supply to the NOx sensor at the silencer outlet T115 is shorted to ground.
What causes Scania DTC 4388?
Electrical fault in the circuit for the voltage supply to NOx sensor at the silencer outlet T115. The circuit is shorted to earth.
How does the system react?
The fault affects the engine's emissions of nitrogen oxides. Depending on the emission class, this results in torque reduction, speed limitation and a warning indication.
How to fix Scania AMS fault code 4388?
- Check the harness-to-harness connector and cable harness for NOx sensor T115.
- Further information about the electrical cables and pins on the control unit to which the component is connected is available under the tab Check for the relevant component.
- Also see Workshop Manual > 03 Fuel and exhaust systems > 03-98 Electronic control system > E67, control unit.
- There is a general description of different troubleshooting methods for electrical faults in Workshop Manual > 16-00 Electrical system, assembly > 16:07-00 General troubleshooting in electrical systems and electronic control systems.
- Verify that the fault has been rectified.
- Turn off the voltage with the starter key, wait until the button for the traffic warning light has gone out, and then turn on the voltage again.
- If the fault is resolved, the fault code becomes inactive.
- Clear the fault code.
- If it doesn't help, change the NOx-sensor.
- The NOx-sensor only has to be plugged in electrically to verify that the fault has been resolved.
This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.