Scania EST DTC 603 Hydraulic cylinder

EST EST control unit · Scania

Code 603 (decimal). Some diagnostic tools show it in hexadecimal as 025B.

In short

The movement of the hydraulic piston does not correspond to the motor pump speed. The piston is moving too slowly in relation to the motor speed.

Applies to: EST1 (EST)

What does Scania EST fault code 603 mean?

The movement of the hydraulic piston does not correspond to the motor pump speed. The piston is moving too slowly in relation to the motor speed.

What causes Scania DTC 603?

- Air in the hydraulic system. - Leaks in the hydraulic system connections. - The piston sealing rings may be damaged. - Leakage from the oil tank. - Defective or seizing valves for operating mode or degraded mode. - The hydraulic pump in the motor pump unit is defective or worn. - Fault in piston position sensor.

How to fix Scania EST fault code 603?

  1. Let the system carry out a diagnostic self-test.
  2. Apply the parking brake and then turn the 15 voltage off and on with the starter key.
  3. Check for active or inactive fault codes which may explain the root cause of the fault.
  4. Check for signs of leakage around hoses and components.
  5. Carry out bleeding of the system.
  6. Check that the solenoid valves for operating mode, degraded mode and mechanical unlocking of the degradation valve are working.

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

Code 603 in other Scania systems

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