Scania BCI DTC 521 Communication fault, CAN bus for expansion units

BCI BCI control unit · Scania · 7 variants

Code 521 (decimal). Some diagnostic tools show it in hexadecimal as 0209.

In short

Communication fault on CAN bus for expansion units.

Variant 1

Applies to: BCI E1 (BWEXA)BCI E1 (BWEXB)BCI E1 (BWEXD)BCI E1 (BWEXE)BCI E1 (BWEXG)BCI E1 (BWEXH)BCI E1 (BWEXI)

What does Scania BCI fault code 521 mean?

What causes Scania DTC 521?

How does the system react?

How to fix Scania BCI fault code 521?

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Variant 2

Applies to: BCI E1 (BWEXC)BCI E1 (BWEXF)

Variant 3: Communication with the tachograph (TCO)

Applies to: BCI1 (BWE)BCI2 (BWE)

Variant 4: Communication with the tachograph (TCO)

Applies to: BCI2 (BWE)

Variant 5: Communication with the tachograph (TCO)

Applies to: BCI3 (BWE)

Variant 6

Applies to: BCI B1 (BWEXBUS)

Variant 7

Applies to: BCI C1 (BWEXI)

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

Code 521 in other Scania systems

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