Applies to: OPC4 (RET)
What does Scania RET fault code 4 mean?
Incorrect or unreliable data.
What causes Scania DTC 4?
Internal fault.
How does the system react?
Retarder braking is not possible. Yellow retarder warning is displayed in the instrument cluster.
How to fix Scania RET fault code 4?
- If updating of software in the control unit is carried out and fails, try repeating the updating.
- Otherwise clear all fault codes, switch off and re-start the vehicle.
- If the fault codes are still displayed, renew the control unit.
This information is for guidance only. Always follow the manufacturer workshop manual and safety procedures; if in doubt, contact an authorised workshop.
Code 4 in other Scania systems
- 4hex 0004 Control unit 2, ACS
- 4hex 000004 Loudspeaker channel 2, short circuit to battery voltage
- 4hex 0004 Control unit
- 4hex 0004 Control unit
- 4hex 0004 Communication with the engine control unit
- 4hex 0004 Control motor in the water valve
- 4hex 0004 Communication with the engine control unit
- 4hex 0004 Activating the radio
- 4hex 000004 CAN communication, open circuit
- 4hex 0004 Control unit
- 4hex 0004 External instrument panel lighting
- 4hex 0004 Voltage supply
- 4hex 0004 Rotational speed sensor
- 4hex 0004 Dipped beam LH.