Power supply and main relay DDE

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:

• Voltage supply to DDE control unit exceeded/below specified value
  
• DDE main relay switches too early or too late