Scania BMU DTC 657 The heater does not respond to activation attempts

BMU Battery Management Unit · Scania · 2 variants

Code 657 (decimal). Some diagnostic tools show it in hexadecimal as 0291.

In short

The heater temperature does not increase as expected.

Variant 1

Applies to: BMU6 (RES)BMU6 (RESXA)BMU6 (RESXB)BMU6 (RESXC)BMU6 (RESXD)BMU6 (RESXE)BMU6 (RESXF)BMU6 (RESXG)BMU6 (RESXH)BMU6 (RESXI)BMU6 (RESXJ)BMU6 (RESXK)

What does Scania BMU fault code 657 mean?

What causes Scania DTC 657?

What are the symptoms?

How to fix Scania BMU fault code 657?

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Variant 2

Applies to: BMU5

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

Code 657 in other Scania systems

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