Scania TMS DTC 768 Timeout when validating immobiliser

TMS Transmission Management System · Scania · 2 variants

Code 768 (decimal). Some diagnostic tools show it in hexadecimal as 0300.

In short

- The validation between the coordinator and the TMS control unit took too long. - Timeout in the immobiliser timer.

Variant 1

Applies to: TMS4 (TMS)TMS5 (TMS)

What does Scania TMS fault code 768 mean?

- The validation between the coordinator and the TMS control unit took too long. - Timeout in the immobiliser timer.

What causes Scania DTC 768?

- The coordinator has been disconnected when starting the TMS control unit. - The coordinator could not verify the starter key. - The 15 voltage has been turned off one or more times shortly after starting, before validation has been completed (which takes about 1 second). - The 30 voltage has been turned off before the 15 voltage. - The status of the immobiliser was not saved the last time, e.g. because the TMS control unit was turned off incorrectly or the battery master switch has been used.

How does the system react?

The electric machine is prevented from starting. If any gear other than neutral is engaged, neutral will immediately be engaged.

How to fix Scania TMS fault code 768?

  1. Check whether there are any active fault codes in the coordinator.
  2. Perform troubleshooting via these.
  3. If there are no active fault codes in the coordinator and the driver has not noticed any problems: Clear the fault code.
  4. After troubleshooting is complete, delete fault codes in the TMS control unit and check whether the fault code appears again.

Variant 2: No CAN message

Applies to: TMS6 (TMS)

Detection

No CAN signal from the gearbox control system sub data bus has been detected.

Possible cause

Fault in the harness-to-component connector or cable harness between the GMS control unit and a sub data bus.

System reaction

A yellow warning indication is displayed.

How to fix

  1. Check the cable harness to the GMS control unit and the sub data bus.
  2. Check the harness-to-component connector to the GMS control unit and the sub data bus.
  3. Check active fault codes set for GMS.

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

Code 768 in other Scania systems

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