Scania TMS DTC 257 Clutch actuator, CAN communication timeout

TMS Transmission Management System · Scania

Code 257 (decimal). Some diagnostic tools show it in hexadecimal as 0101.

In short

The Transmission Management System (TMS) has detected a communication failure with the clutch actuator (ECA).

Applies to: TMS3 (TMS)

What does Scania TMS fault code 257 mean?

The Transmission Management System (TMS) has detected a communication failure with the clutch actuator (ECA).

What causes Scania DTC 257?

- Open circuit in harness-to-harness connector or CAN bus harness-to-component connector. - Open circuit in the voltage supply to the clutch actuator. - The message has not been transferred by the clutch actuator. - Incorrect version of ECA has been fitted. - TMS is not configured correctly. - Voltage from the battery is too low.

How does the system react?

- A yellow warning indication is displayed. - If the vehicle is stationary: neutral position is activated, which prevents the vehicle from being driven further. - If the vehicle is being driven: the gear is put into locked position and neutral position is activated in the event of brake application, which prevents the vehicle from being driven further.

How to fix Scania TMS fault code 257?

  1. Check the cable harness and harness-to-harness connector for the transmission management system (E5) and clutch actuator (E93).
  2. Check that the TMS configuration matches that of the clutch actuator, ECA.
  3. Charge the batteries and check the battery state of health with a battery tester.
  4. For more information, see Multi > 16–25.
  5. Renew batteries that are not fully functional.
  6. Check for software updates for the transmission management system (E5), TMS.
  7. Check for software updates for the clutch actuator (E93), ECA.
  8. Renew the clutch actuator, ECA, if the problem persists.

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

Code 257 in other Scania systems

Compare code 257 in every system →