Power Supply And DDE Main Relay

Power Supply And DDE Main Relay

The power supply for the DDE control unit is provided via the 8-pin control unit connector.

Function
The power supply to the DDE control unit follows the following sequence when the ignition is switched on:
- With ignition ON, voltage is applied to the DDE control unit via terminal 15WUP and terminal 15_3.
- The DDE main relay is switched via the signal 30B.
- 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 254E00/254D00: Voltage of power supply to DDE control unit too high/low
- Fault code 274900: DDE main relay switches off too early, possibly due to undervoltage.