Direct Current To Direct Current Converter
| Item | Description |
|---|---|
| 1 | 12V output connection to Battery Junction Box (BJB) |
| 2 | Direct Current to Direct Current (DC/DC) converter |
| 3 | Engine coolant connection |
| 4 | High Voltage (HV) connector from the High Voltage Junction Box (HVJB) |
| 5 | Engine coolant connection |
| 6 | Pressure equalizer connection |
| 7 | Wiring harness connector |
| 8 | Electrical bonding cable connection |
The Direct Current to Direct Current (DC/DC) converter is located under the floorpan of the vehicle on the right side, above the Electric Power Inverter Converter (EPIC).
The DC/DC converter is supplied with power from the PHEV battery. The DC/DC converts the high voltage supply from the PHEV battery to the 12V for the vehicles startup battery. This charges the 12V startup battery and provides all the electrical power for all the 12V components. The output from the DC/DC converter is approximately 14V. The DC/DC converter supplies all the power for the startup battery and for all the vehicle 12V systems.
The high voltage circuit and the low voltage circuit are isolated from each other in a 'Galvanic Isolation'. This prevents the high voltage and the low voltage electric circuits from being connected together.
The DC/DC converter has 4 electrical connections:
- High voltage cable from the High Voltage Junction Box (HVJB).
- Bonding cable connection to vehicle chassis.
- 12V output to startup battery, auxiliary battery and the vehicle 12V systems.
- Wiring harness connector, 8 pin for:
- High voltage interlock loop (2 off).
- 12V supply.
- High Speed (HS) Controller Area Network (CAN) power mode zero bus (2 off).
- A ground connection.
The HS CAN power mode zero bus is also connected to these:
- The PHEV battery
- The EPIC
- The PHEV battery onboard charger
- The Body Control Module/Gateway Module (BCM/GWM)
The DC/DC converter has 2 engine coolant connections to provide cooling. The flow of engine coolant is controlled by the EPIC. The EPIC controls an electric coolant pump to regulate the flow of engine coolant depending on cooling requirements.
The DC/DC converter has a connection for pressure equalisation. This connects via pipes and hoses to the atmosphere on the rear left of the engine compartment. This allows the pressure inside the DC/DC converter to equalize with the atmospheric pressure preventing a pressure or vacuum inside the DC/DC converter.