Scania EEC DTC 4378 Reductant pump, open circuit or short circuit

EEC Exhaust Emission Control · Scania

Code 4378 (decimal). Some diagnostic tools show it in hexadecimal as 111A.

In short

Fault in the reductant pump control and voltage supply circuit.

Applies to: EEC3

What does Scania EEC fault code 4378 mean?

What causes Scania DTC 4378?

How does the system react?

How to fix Scania EEC fault code 4378?

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

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