Scania ALM DTC 521 Micro switch rear door passenger side (truck)/micro switch A4 (bus), short circuit

ALM ALM control unit · Scania · 2 variants

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

In short

The micro switch is short-circuited to the voltage supply.

Variant 1

Applies to: ALM1 (ALM)

What does Scania ALM fault code 521 mean?

What causes Scania DTC 521?

How does the system react?

What are the symptoms?

How to fix Scania ALM fault code 521?

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Variant 2

Applies to: ALM1

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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