Scania BMU DTC 633 Internal insulation fault in the propulsion battery

BMU Battery Management Unit · Scania · 2 variants

Code 633 (decimal). Some diagnostic tools show it in hexadecimal as 0279.

In short

The electrical insulation between the negative terminal or the positive terminal and earth for the propulsion battery is too low, lower than 4 kohm.

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 633 mean?

What causes Scania DTC 633?

How does the system react?

How to fix Scania BMU fault code 633?

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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 633 in other Scania systems

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