Scania EMU DTC 4227 Heater H40, internal fault

EMU EMU control unit · Scania

Code 4227 (decimal). Some diagnostic tools show it in hexadecimal as 001083.

In short

The heater is reporting that the primary transistor current is over 500 mA, while the PWM signal to both heater elements is low.

Applies to: EMU1 (ECS)

What does Scania EMU fault code 4227 mean?

What causes Scania DTC 4227?

How does the system react?

What are the symptoms?

How to fix Scania EMU fault code 4227?

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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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