Scania fault code 4420
Code 4420 is used by 2 different Scania systems. Choose the control unit shown in your diagnostic tool:
EMS Engine Management System
Coolant temperature sensor, unexpectedly high value
The control unit has interpreted the value from the coolant temperature sensor as higher than expected.
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AMS
Communication error, requested urea quantity V231 from EMS
The EEC control unit has detected an error in the CAN communication from the EMS control unit regarding the requested urea quantity.
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