Scania TMS DTC 21021 CAN communication from BMS

TMS Transmission Management System · Scania · 3 variants

Code 21021 (decimal). Some diagnostic tools show it in hexadecimal as 521D.

In short

Timeout from the brake system when the control unit supply voltage is low.

Variant 1

Applies to: TMS1

What does Scania TMS fault code 21021 mean?

What causes Scania DTC 21021?

How does the system react?

How to fix Scania TMS fault code 21021?

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Variant 2

Applies to: TMS2 (TMS)

Variant 3

Applies to: TMSe2 (TMS)

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

Code 21021 in other Scania systems