Scania RET DTC 28677 The synchromesh actuating arm is disengaged when the solenoid valve is activated

RET Retarder · Scania

Code 28677 (decimal). Some diagnostic tools show it in hexadecimal as 7005.

In short

The solenoid valve for operating the actuating arm is activated and the actuating arm should be engaged, but jumps out of the engaged position.

Applies to: OPC5 (RET2)

What does Scania RET fault code 28677 mean?

What causes Scania DTC 28677?

How does the system react?

How to fix Scania RET fault code 28677?

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

Code 28677 in other Scania systems