Voltage Supply and Main Relay DDE 3.0

Function

The voltage supply of the DDE control unit is based on following stages:

• At ignition ON, voltage is applied to the DDE control unit via terminal 15
  
• The DDE control unit switches the DDE main relay via S_HR
  
• The DDE main relay switches terminal 30 via U_HR to the DDE control unit
  

Troubleshooting

The following faults are monitored in the voltage supply system:

• Fault code 10: Voltage supply to DDE control unit or injection pump exceeded/below specified value
  
• Fault code 12: Terminal 15
  
• Fault code 13: DDE main relay switches too early or too late
  

Consequences:

• Fault code 10: The system switches over from start of injection closed-loop control to start of injection open-loop control and exhaust gas recirculation is deactivated
  
• Fault code 12: Engine shuts down
  
• Fault code 13: None