Scania CMS DTC 546 Unknown control unit

CMS CMS control unit · Scania

Code 546 (decimal). Some diagnostic tools show it in hexadecimal as 0222.

In short

An unknown control unit has been detected.

Applies to: CMS1 (CMS)

What does Scania CMS fault code 546 mean?

An unknown control unit has been detected.

What causes Scania DTC 546?

The fault may be due to: A control unit with software that is not compatible with the vehicle having been connected to the CMS control unit sub data bus 1. - A reused control unit having a newer version of the software than the rest of the vehicle. - A replacement control unit having a newer version of the software than the rest of the vehicle. A CMS control unit with software that is not compatible with the vehicle having been installed. - The CMS control unit used as a spare part having an older version of the software than the rest of the vehicle.

What are the symptoms?

- The operational data cannot be saved as long as the fault code is active. - The vehicle may display unexpected behaviour if a control unit is incorrectly configured.

How to fix Scania CMS fault code 546?

  1. Renew the control unit that has a different version of the software from the rest of the vehicle.
  2. Tip: If any control unit has been retrofitted on the CMS control unit sub data bus 1, check it.
  3. Check the control unit that has most recently been renewed as a spare part.

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

Code 546 in other Scania systems

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