ENGINE | 780.993 in MODEL 451.390/392/490/492 |
Location
The high-voltage battery drive switchover valve is located on the underside of the vehicle at the rear right.
M5 | Electric drive motor |
N83 | 3kW onboard charger (for code (908) 22KW onboard charger) |
N83/10 | 22kW onboard charger (for code (908) KW onboard charger 22KW) |
N129/1 | Power electronics control unit |
Y133/1 | Drive coolant pump switchover valve |
P20.10-2349-76
Task
The high-voltage battery drive switchover valve regulates the flow of coolant between the electric motor drive and the onboard charger.
Function
The high-voltage battery drive switchover valve is actuated directly by the drivetrain control unit (N127). For charging mode the drivetrain control unit applies the positive potential on pin 2 on the connector for the drive coolant pump switchover valve. The positive potential is applied to pin 1 in driving mode.
This pole reversal of the potential alter the direction of flow in the drive coolant pump switchover valve.
This change allows flow through of the onboard charger with coolant in charging mode and through the electric motor drive in driving mode.
The power electronics control unit is flowed through with coolant in both cases.
In a deenergized condition the drive coolant pump switchover valve remains in the previously taken position.