Scania AMS DTC 4421 Communication error, requested urea quantity V117 from EMS

AMS AMS control unit · Scania

Code 4421 (decimal). Some diagnostic tools show it in hexadecimal as 001145.

In short

The EEC control unit has detected an error in the CAN communication from the EMS control unit regarding the requested urea quantity.

Applies to: AMS2

What does Scania AMS fault code 4421 mean?

The EEC control unit has detected an error in the CAN communication from the EMS control unit regarding the requested urea quantity.

What causes Scania DTC 4421?

Secondary fault. - Software bug in the engine control unit. - Fault in the cable harness or harness-to-harness connector between the EEC control unit and the engine control unit. - Internal fault in the engine control unit.

How to fix Scania AMS fault code 4421?

  1. Check primary fault codes in EMS.
  2. Check the engine control unit software version.
  3. Update the software if necessary.
  4. If the fault persists, create a defect report.

This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.

Code 4421 in other Scania systems

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